diff --git a/src/test/ui/borrowck/issue-64453.rs b/src/test/ui/borrowck/issue-64453.rs
index 9e70a847457..33d55be5812 100644
--- a/src/test/ui/borrowck/issue-64453.rs
+++ b/src/test/ui/borrowck/issue-64453.rs
@@ -2,7 +2,7 @@ struct Project;
 struct Value;
 
 static settings_dir: String = format!("");
-//~^ ERROR calls in statics are limited to constant functions
+//~^ ERROR cannot call non-const fn
 //~| ERROR is not yet stable as a const
 
 fn from_string(_: String) -> Value {
diff --git a/src/test/ui/borrowck/issue-64453.stderr b/src/test/ui/borrowck/issue-64453.stderr
index 14e16670389..f3436fbec66 100644
--- a/src/test/ui/borrowck/issue-64453.stderr
+++ b/src/test/ui/borrowck/issue-64453.stderr
@@ -7,12 +7,13 @@ LL | static settings_dir: String = format!("");
    = help: add `#![feature(const_fmt_arguments_new)]` to the crate attributes to enable
    = note: this error originates in the macro `$crate::__export::format_args` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error[E0015]: calls in statics are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `format` in statics
   --> $DIR/issue-64453.rs:4:31
    |
 LL | static settings_dir: String = format!("");
    |                               ^^^^^^^^^^^
    |
+   = note: calls in statics are limited to constant functions, tuple structs and tuple variants
    = note: this error originates in the macro `format` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0507]: cannot move out of static item `settings_dir`
diff --git a/src/test/ui/check-static-values-constraints.rs b/src/test/ui/check-static-values-constraints.rs
index 3d1b5a08227..eb4ecd8baca 100644
--- a/src/test/ui/check-static-values-constraints.rs
+++ b/src/test/ui/check-static-values-constraints.rs
@@ -87,7 +87,7 @@ static mut STATIC13: SafeStruct = SafeStruct{field1: SafeEnum::Variant1,
 static mut STATIC14: SafeStruct = SafeStruct {
     field1: SafeEnum::Variant1,
     field2: SafeEnum::Variant4("str".to_string())
-//~^ ERROR calls in statics are limited to constant functions
+//~^ ERROR cannot call non-const fn
 };
 
 static STATIC15: &'static [Box<MyOwned>] = &[
diff --git a/src/test/ui/check-static-values-constraints.stderr b/src/test/ui/check-static-values-constraints.stderr
index eb640c88e02..b28cf0d6bd0 100644
--- a/src/test/ui/check-static-values-constraints.stderr
+++ b/src/test/ui/check-static-values-constraints.stderr
@@ -15,11 +15,13 @@ error[E0010]: allocations are not allowed in statics
 LL | static STATIC11: Box<MyOwned> = box MyOwned;
    |                                 ^^^^^^^^^^^ allocation not allowed in statics
 
-error[E0015]: calls in statics are limited to constant functions, tuple structs and tuple variants
-  --> $DIR/check-static-values-constraints.rs:89:32
+error[E0015]: cannot call non-const fn `<str as ToString>::to_string` in statics
+  --> $DIR/check-static-values-constraints.rs:89:38
    |
 LL |     field2: SafeEnum::Variant4("str".to_string())
-   |                                ^^^^^^^^^^^^^^^^^
+   |                                      ^^^^^^^^^^^
+   |
+   = note: calls in statics are limited to constant functions, tuple structs and tuple variants
 
 error[E0010]: allocations are not allowed in statics
   --> $DIR/check-static-values-constraints.rs:94:5
diff --git a/src/test/ui/const-generics/nested-type.full.stderr b/src/test/ui/const-generics/nested-type.full.stderr
index 9d7ca36545c..52f1c588258 100644
--- a/src/test/ui/const-generics/nested-type.full.stderr
+++ b/src/test/ui/const-generics/nested-type.full.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in constants are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `Foo::{constant#0}::Foo::<17_usize>::value` in constants
   --> $DIR/nested-type.rs:15:5
    |
 LL |     Foo::<17>::value()
    |     ^^^^^^^^^^^^^^^^^^
+   |
+   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/nested-type.min.stderr b/src/test/ui/const-generics/nested-type.min.stderr
index 4f32284ecb1..0e3c988ae4d 100644
--- a/src/test/ui/const-generics/nested-type.min.stderr
+++ b/src/test/ui/const-generics/nested-type.min.stderr
@@ -14,11 +14,13 @@ LL | | }]>;
    = note: the only supported types are integers, `bool` and `char`
    = help: more complex types are supported with `#![feature(adt_const_params)]`
 
-error[E0015]: calls in constants are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `Foo::{constant#0}::Foo::<17_usize>::value` in constants
   --> $DIR/nested-type.rs:15:5
    |
 LL |     Foo::<17>::value()
    |     ^^^^^^^^^^^^^^^^^^
+   |
+   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/const-generics/nested-type.rs b/src/test/ui/const-generics/nested-type.rs
index 039f996de96..5240f5c3b0b 100644
--- a/src/test/ui/const-generics/nested-type.rs
+++ b/src/test/ui/const-generics/nested-type.rs
@@ -13,7 +13,7 @@ struct Foo<const N: [u8; { //[min]~ ERROR `[u8; _]` is forbidden
     }
 
     Foo::<17>::value()
-    //~^ ERROR calls in constants are limited to constant functions
+    //~^ ERROR cannot call non-const fn
 }]>;
 
 fn main() {}
diff --git a/src/test/ui/consts/const-call.rs b/src/test/ui/consts/const-call.rs
index db642988971..28e89559fe5 100644
--- a/src/test/ui/consts/const-call.rs
+++ b/src/test/ui/consts/const-call.rs
@@ -4,5 +4,5 @@ fn f(x: usize) -> usize {
 
 fn main() {
     let _ = [0; f(2)];
-    //~^ ERROR calls in constants are limited to constant functions
+    //~^ ERROR cannot call non-const fn
 }
diff --git a/src/test/ui/consts/const-call.stderr b/src/test/ui/consts/const-call.stderr
index 9761348bab8..e46bcad0e1d 100644
--- a/src/test/ui/consts/const-call.stderr
+++ b/src/test/ui/consts/const-call.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in constants are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `f` in constants
   --> $DIR/const-call.rs:6:17
    |
 LL |     let _ = [0; f(2)];
    |                 ^^^^
+   |
+   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/consts/const-extern-fn/const-extern-fn-call-extern-fn.rs b/src/test/ui/consts/const-extern-fn/const-extern-fn-call-extern-fn.rs
index ee07dfae47c..eccda49db3e 100644
--- a/src/test/ui/consts/const-extern-fn/const-extern-fn-call-extern-fn.rs
+++ b/src/test/ui/consts/const-extern-fn/const-extern-fn-call-extern-fn.rs
@@ -7,7 +7,7 @@ extern "C" {
 const extern "C" fn bar() {
     unsafe {
         regular_in_block();
-        //~^ ERROR: calls in constant functions
+        //~^ ERROR: cannot call non-const fn
     }
 }
 
@@ -16,7 +16,7 @@ extern "C" fn regular() {}
 const extern "C" fn foo() {
     unsafe {
         regular();
-        //~^ ERROR: calls in constant functions
+        //~^ ERROR: cannot call non-const fn
     }
 }
 
diff --git a/src/test/ui/consts/const-extern-fn/const-extern-fn-call-extern-fn.stderr b/src/test/ui/consts/const-extern-fn/const-extern-fn-call-extern-fn.stderr
index 348387ff5f8..5acf22e4bc6 100644
--- a/src/test/ui/consts/const-extern-fn/const-extern-fn-call-extern-fn.stderr
+++ b/src/test/ui/consts/const-extern-fn/const-extern-fn-call-extern-fn.stderr
@@ -1,14 +1,18 @@
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `regular_in_block` in constant functions
   --> $DIR/const-extern-fn-call-extern-fn.rs:9:9
    |
 LL |         regular_in_block();
    |         ^^^^^^^^^^^^^^^^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `regular` in constant functions
   --> $DIR/const-extern-fn-call-extern-fn.rs:18:9
    |
 LL |         regular();
    |         ^^^^^^^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/consts/const-fn-error.rs b/src/test/ui/consts/const-fn-error.rs
index 065944ea7ea..0b813e65621 100644
--- a/src/test/ui/consts/const-fn-error.rs
+++ b/src/test/ui/consts/const-fn-error.rs
@@ -4,8 +4,9 @@ const fn f(x: usize) -> usize {
     let mut sum = 0;
     for i in 0..x {
         //~^ ERROR mutable references
-        //~| ERROR calls in constant functions
-        //~| ERROR calls in constant functions
+        //~| ERROR cannot convert
+        //~| ERROR cannot call non-const fn
+        //~| ERROR E0080
         //~| ERROR `for` is not allowed in a `const fn`
         sum += i;
     }
diff --git a/src/test/ui/consts/const-fn-error.stderr b/src/test/ui/consts/const-fn-error.stderr
index e4b62f20a33..4d53cfc35e1 100644
--- a/src/test/ui/consts/const-fn-error.stderr
+++ b/src/test/ui/consts/const-fn-error.stderr
@@ -13,11 +13,18 @@ LL | |     }
    = note: see issue #87575 <https://github.com/rust-lang/rust/issues/87575> for more information
    = help: add `#![feature(const_for)]` to the crate attributes to enable
 
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot convert `std::ops::Range<usize>` into an iterator in constant functions
   --> $DIR/const-fn-error.rs:5:14
    |
 LL |     for i in 0..x {
    |              ^^^^
+   |
+note: impl defined here, but it is not `const`
+  --> $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL
+   |
+LL | impl<I: Iterator> IntoIterator for I {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
 error[E0658]: mutable references are not allowed in constant functions
   --> $DIR/const-fn-error.rs:5:14
@@ -28,11 +35,13 @@ LL |     for i in 0..x {
    = note: see issue #57349 <https://github.com/rust-lang/rust/issues/57349> for more information
    = help: add `#![feature(const_mut_refs)]` to the crate attributes to enable
 
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `<std::ops::Range<usize> as Iterator>::next` in constant functions
   --> $DIR/const-fn-error.rs:5:14
    |
 LL |     for i in 0..x {
    |              ^^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to 4 previous errors
 
diff --git a/src/test/ui/consts/const-fn-not-safe-for-const.stderr b/src/test/ui/consts/const-fn-not-safe-for-const.stderr
index df793d7dd7e..4c7effc0d15 100644
--- a/src/test/ui/consts/const-fn-not-safe-for-const.stderr
+++ b/src/test/ui/consts/const-fn-not-safe-for-const.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `random` in constant functions
   --> $DIR/const-fn-not-safe-for-const.rs:14:5
    |
 LL |     random()
    |     ^^^^^^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
 error[E0013]: constant functions cannot refer to statics
   --> $DIR/const-fn-not-safe-for-const.rs:20:5
diff --git a/src/test/ui/consts/const-for.rs b/src/test/ui/consts/const-for.rs
index 5fc1ee0e369..58bcb5f74cc 100644
--- a/src/test/ui/consts/const-for.rs
+++ b/src/test/ui/consts/const-for.rs
@@ -3,8 +3,8 @@
 
 const _: () = {
     for _ in 0..5 {}
-    //~^ error: calls in constants are limited to
-    //~| error: calls in constants are limited to
+    //~^ error: cannot convert
+    //~| error: cannot call non-const fn
 };
 
 fn main() {}
diff --git a/src/test/ui/consts/const-for.stderr b/src/test/ui/consts/const-for.stderr
index a35c04b3570..b0dc43eb8e8 100644
--- a/src/test/ui/consts/const-for.stderr
+++ b/src/test/ui/consts/const-for.stderr
@@ -1,14 +1,23 @@
-error[E0015]: calls in constants are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot convert `std::ops::Range<i32>` into an iterator in constants
   --> $DIR/const-for.rs:5:14
    |
 LL |     for _ in 0..5 {}
    |              ^^^^
+   |
+note: impl defined here, but it is not `const`
+  --> $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL
+   |
+LL | impl<I: Iterator> IntoIterator for I {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
 
-error[E0015]: calls in constants are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `<std::ops::Range<i32> as Iterator>::next` in constants
   --> $DIR/const-for.rs:5:14
    |
 LL |     for _ in 0..5 {}
    |              ^^^^
+   |
+   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/consts/control-flow/issue-46843.rs b/src/test/ui/consts/control-flow/issue-46843.rs
index edf62f23266..ddddc8505c6 100644
--- a/src/test/ui/consts/control-flow/issue-46843.rs
+++ b/src/test/ui/consts/control-flow/issue-46843.rs
@@ -8,7 +8,7 @@ fn non_const() -> Thing {
 }
 
 pub const Q: i32 = match non_const() {
-    //~^ ERROR calls in constants are limited to constant functions
+    //~^ ERROR cannot call non-const fn
     Thing::This => 1,
     Thing::That => 0
 };
diff --git a/src/test/ui/consts/control-flow/issue-46843.stderr b/src/test/ui/consts/control-flow/issue-46843.stderr
index ea9ea25f9e1..66227f61e35 100644
--- a/src/test/ui/consts/control-flow/issue-46843.stderr
+++ b/src/test/ui/consts/control-flow/issue-46843.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in constants are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `non_const` in constants
   --> $DIR/issue-46843.rs:10:26
    |
 LL | pub const Q: i32 = match non_const() {
    |                          ^^^^^^^^^^^
+   |
+   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/consts/intrinsic_without_const_stab.rs b/src/test/ui/consts/intrinsic_without_const_stab.rs
index 810158a2957..d5f694986fc 100644
--- a/src/test/ui/consts/intrinsic_without_const_stab.rs
+++ b/src/test/ui/consts/intrinsic_without_const_stab.rs
@@ -11,7 +11,7 @@ pub const unsafe fn copy<T>(src: *const T, dst: *mut T, count: usize) {
     }
 
     unsafe { copy(src, dst, count) }
-    //~^ ERROR calls in constant functions are limited to constant functions
+    //~^ ERROR cannot call non-const fn
 }
 
 fn main() {}
diff --git a/src/test/ui/consts/intrinsic_without_const_stab.stderr b/src/test/ui/consts/intrinsic_without_const_stab.stderr
index 5a42823a605..b32b6398ece 100644
--- a/src/test/ui/consts/intrinsic_without_const_stab.stderr
+++ b/src/test/ui/consts/intrinsic_without_const_stab.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `copy::copy::<T>` in constant functions
   --> $DIR/intrinsic_without_const_stab.rs:13:14
    |
 LL |     unsafe { copy(src, dst, count) }
    |              ^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/consts/intrinsic_without_const_stab_fail.rs b/src/test/ui/consts/intrinsic_without_const_stab_fail.rs
index bf2c44169d4..8b37268b0b2 100644
--- a/src/test/ui/consts/intrinsic_without_const_stab_fail.rs
+++ b/src/test/ui/consts/intrinsic_without_const_stab_fail.rs
@@ -9,7 +9,7 @@ extern "rust-intrinsic" {
 #[rustc_const_unstable(feature = "const_intrinsic_copy", issue = "80697")]
 #[inline]
 pub const unsafe fn stuff<T>(src: *const T, dst: *mut T, count: usize) {
-    unsafe { copy(src, dst, count) } //~ ERROR calls in constant functions are limited
+    unsafe { copy(src, dst, count) } //~ ERROR cannot call non-const fn
 }
 
 fn main() {}
diff --git a/src/test/ui/consts/intrinsic_without_const_stab_fail.stderr b/src/test/ui/consts/intrinsic_without_const_stab_fail.stderr
index d4a2989e785..fcbb3724567 100644
--- a/src/test/ui/consts/intrinsic_without_const_stab_fail.stderr
+++ b/src/test/ui/consts/intrinsic_without_const_stab_fail.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `copy::<T>` in constant functions
   --> $DIR/intrinsic_without_const_stab_fail.rs:12:14
    |
 LL |     unsafe { copy(src, dst, count) }
    |              ^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/consts/issue-28113.rs b/src/test/ui/consts/issue-28113.rs
index e5bd7aafe41..1d93d454af7 100644
--- a/src/test/ui/consts/issue-28113.rs
+++ b/src/test/ui/consts/issue-28113.rs
@@ -2,7 +2,7 @@
 
 const X: u8 =
     || -> u8 { 5 }()
-    //~^ ERROR calls in constants are limited to constant functions
+    //~^ ERROR cannot call non-const fn
 ;
 
 fn main() {}
diff --git a/src/test/ui/consts/issue-28113.stderr b/src/test/ui/consts/issue-28113.stderr
index 3d274d777b0..75fcc010a04 100644
--- a/src/test/ui/consts/issue-28113.stderr
+++ b/src/test/ui/consts/issue-28113.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in constants are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `<[closure@$DIR/issue-28113.rs:4:5: 4:19] as Fn<()>>::call` in constants
   --> $DIR/issue-28113.rs:4:5
    |
 LL |     || -> u8 { 5 }()
    |     ^^^^^^^^^^^^^^^^
+   |
+   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/consts/issue-32829-2.rs b/src/test/ui/consts/issue-32829-2.rs
index e0fcf278330..d70b5a8c4e1 100644
--- a/src/test/ui/consts/issue-32829-2.rs
+++ b/src/test/ui/consts/issue-32829-2.rs
@@ -8,7 +8,7 @@ const bad : u32 = {
 const bad_two : u32 = {
     {
         invalid();
-        //~^ ERROR: calls in constants are limited to constant functions, tuple structs and tuple variants
+        //~^ ERROR: cannot call non-const fn `invalid`
         0
     }
 };
@@ -30,7 +30,7 @@ static bad_four : u32 = {
 static bad_five : u32 = {
     {
         invalid();
-        //~^ ERROR: calls in statics are limited to constant functions, tuple structs and tuple variants
+        //~^ ERROR: cannot call non-const fn `invalid`
         0
     }
 };
@@ -52,7 +52,7 @@ static mut bad_seven : u32 = {
 static mut bad_eight : u32 = {
     {
         invalid();
-        //~^ ERROR: calls in statics are limited to constant functions, tuple structs and tuple variants
+        //~^ ERROR: cannot call non-const fn `invalid`
         0
     }
 };
diff --git a/src/test/ui/consts/issue-32829-2.stderr b/src/test/ui/consts/issue-32829-2.stderr
index 1d265875c5c..b94bdc0e3df 100644
--- a/src/test/ui/consts/issue-32829-2.stderr
+++ b/src/test/ui/consts/issue-32829-2.stderr
@@ -1,20 +1,26 @@
-error[E0015]: calls in constants are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `invalid` in constants
   --> $DIR/issue-32829-2.rs:10:9
    |
 LL |         invalid();
    |         ^^^^^^^^^
+   |
+   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
 
-error[E0015]: calls in statics are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `invalid` in statics
   --> $DIR/issue-32829-2.rs:32:9
    |
 LL |         invalid();
    |         ^^^^^^^^^
+   |
+   = note: calls in statics are limited to constant functions, tuple structs and tuple variants
 
-error[E0015]: calls in statics are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `invalid` in statics
   --> $DIR/issue-32829-2.rs:54:9
    |
 LL |         invalid();
    |         ^^^^^^^^^
+   |
+   = note: calls in statics are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/consts/issue-43105.rs b/src/test/ui/consts/issue-43105.rs
index cc6a4850853..cac12b90970 100644
--- a/src/test/ui/consts/issue-43105.rs
+++ b/src/test/ui/consts/issue-43105.rs
@@ -1,7 +1,7 @@
 fn xyz() -> u8 { 42 }
 
 const NUM: u8 = xyz();
-//~^ ERROR calls in constants are limited to constant functions, tuple structs and tuple variants
+//~^ ERROR cannot call non-const fn
 
 fn main() {
     match 1 {
diff --git a/src/test/ui/consts/issue-43105.stderr b/src/test/ui/consts/issue-43105.stderr
index e508cbdd1dd..2d1174af71c 100644
--- a/src/test/ui/consts/issue-43105.stderr
+++ b/src/test/ui/consts/issue-43105.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in constants are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `xyz` in constants
   --> $DIR/issue-43105.rs:3:17
    |
 LL | const NUM: u8 = xyz();
    |                 ^^^^^
+   |
+   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
 
 error: could not evaluate constant pattern
   --> $DIR/issue-43105.rs:8:9
diff --git a/src/test/ui/consts/issue-56164.rs b/src/test/ui/consts/issue-56164.rs
index 90ea217698d..af65720916c 100644
--- a/src/test/ui/consts/issue-56164.rs
+++ b/src/test/ui/consts/issue-56164.rs
@@ -1,7 +1,7 @@
 #![feature(const_fn_fn_ptr_basics)]
 
 const fn foo() { (||{})() }
-//~^ ERROR calls in constant functions
+//~^ ERROR cannot call non-const fn
 
 const fn bad(input: fn()) {
     input()
diff --git a/src/test/ui/consts/issue-56164.stderr b/src/test/ui/consts/issue-56164.stderr
index 500af0a4006..af5d44d4814 100644
--- a/src/test/ui/consts/issue-56164.stderr
+++ b/src/test/ui/consts/issue-56164.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `<[closure@$DIR/issue-56164.rs:3:18: 3:24] as Fn<()>>::call` in constant functions
   --> $DIR/issue-56164.rs:3:18
    |
 LL | const fn foo() { (||{})() }
    |                  ^^^^^^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
 error: function pointers are not allowed in const fn
   --> $DIR/issue-56164.rs:7:5
diff --git a/src/test/ui/consts/issue-68542-closure-in-array-len.rs b/src/test/ui/consts/issue-68542-closure-in-array-len.rs
index d77fd9aa831..44f44da234a 100644
--- a/src/test/ui/consts/issue-68542-closure-in-array-len.rs
+++ b/src/test/ui/consts/issue-68542-closure-in-array-len.rs
@@ -3,7 +3,7 @@
 // in the length part of an array.
 
 struct Bug {
-    a: [(); (|| { 0 })()] //~ ERROR calls in constants are limited to
+    a: [(); (|| { 0 })()] //~ ERROR cannot call non-const fn
 }
 
 fn main() {}
diff --git a/src/test/ui/consts/issue-68542-closure-in-array-len.stderr b/src/test/ui/consts/issue-68542-closure-in-array-len.stderr
index 74d70e18a24..3787138afc3 100644
--- a/src/test/ui/consts/issue-68542-closure-in-array-len.stderr
+++ b/src/test/ui/consts/issue-68542-closure-in-array-len.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in constants are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `<[closure@$DIR/issue-68542-closure-in-array-len.rs:6:13: 6:23] as Fn<()>>::call` in constants
   --> $DIR/issue-68542-closure-in-array-len.rs:6:13
    |
 LL |     a: [(); (|| { 0 })()]
    |             ^^^^^^^^^^^^
+   |
+   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/consts/min_const_fn/bad_const_fn_body_ice.rs b/src/test/ui/consts/min_const_fn/bad_const_fn_body_ice.rs
index 4e1b7bf119c..258997597ea 100644
--- a/src/test/ui/consts/min_const_fn/bad_const_fn_body_ice.rs
+++ b/src/test/ui/consts/min_const_fn/bad_const_fn_body_ice.rs
@@ -1,7 +1,7 @@
 const fn foo(a: i32) -> Vec<i32> {
     vec![1, 2, 3]
     //~^ ERROR allocations are not allowed
-    //~| ERROR calls in constant functions
+    //~| ERROR cannot call non-const fn
 }
 
 fn main() {}
diff --git a/src/test/ui/consts/min_const_fn/bad_const_fn_body_ice.stderr b/src/test/ui/consts/min_const_fn/bad_const_fn_body_ice.stderr
index fee43864e20..74234108911 100644
--- a/src/test/ui/consts/min_const_fn/bad_const_fn_body_ice.stderr
+++ b/src/test/ui/consts/min_const_fn/bad_const_fn_body_ice.stderr
@@ -6,12 +6,13 @@ LL |     vec![1, 2, 3]
    |
    = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `slice::<impl [i32]>::into_vec::<std::alloc::Global>` in constant functions
   --> $DIR/bad_const_fn_body_ice.rs:2:5
    |
 LL |     vec![1, 2, 3]
    |     ^^^^^^^^^^^^^
    |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
    = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to 2 previous errors
diff --git a/src/test/ui/consts/mir_check_nonconst.rs b/src/test/ui/consts/mir_check_nonconst.rs
index b8ec0c3c449..b6f34b922fa 100644
--- a/src/test/ui/consts/mir_check_nonconst.rs
+++ b/src/test/ui/consts/mir_check_nonconst.rs
@@ -6,6 +6,6 @@ fn bar() -> Foo {
 }
 
 static foo: Foo = bar();
-//~^ ERROR calls in statics are limited to constant functions, tuple structs and tuple variants
+//~^ ERROR cannot call non-const fn
 
 fn main() {}
diff --git a/src/test/ui/consts/mir_check_nonconst.stderr b/src/test/ui/consts/mir_check_nonconst.stderr
index 30f68ba4372..2bac995eebf 100644
--- a/src/test/ui/consts/mir_check_nonconst.stderr
+++ b/src/test/ui/consts/mir_check_nonconst.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in statics are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `bar` in statics
   --> $DIR/mir_check_nonconst.rs:8:19
    |
 LL | static foo: Foo = bar();
    |                   ^^^^^
+   |
+   = note: calls in statics are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/consts/unstable-const-fn-in-libcore.stderr b/src/test/ui/consts/unstable-const-fn-in-libcore.stderr
index 928605356a1..435141134cb 100644
--- a/src/test/ui/consts/unstable-const-fn-in-libcore.stderr
+++ b/src/test/ui/consts/unstable-const-fn-in-libcore.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `<F as FnOnce<()>>::call_once` in constant functions
   --> $DIR/unstable-const-fn-in-libcore.rs:24:26
    |
 LL |             Opt::None => f(),
    |                          ^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
 error[E0493]: destructors cannot be evaluated at compile-time
   --> $DIR/unstable-const-fn-in-libcore.rs:19:53
diff --git a/src/test/ui/issues/issue-16538.mir.stderr b/src/test/ui/issues/issue-16538.mir.stderr
index 5a276f27886..60a2bf1e2d6 100644
--- a/src/test/ui/issues/issue-16538.mir.stderr
+++ b/src/test/ui/issues/issue-16538.mir.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in statics are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `Y::foo` in statics
   --> $DIR/issue-16538.rs:15:23
    |
 LL | static foo: &Y::X = &*Y::foo(Y::x as *const Y::X);
    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: calls in statics are limited to constant functions, tuple structs and tuple variants
 
 error[E0133]: use of extern static is unsafe and requires unsafe function or block
   --> $DIR/issue-16538.rs:15:30
diff --git a/src/test/ui/issues/issue-16538.thir.stderr b/src/test/ui/issues/issue-16538.thir.stderr
index 8365a1dbf6e..2ba9dfa2bc5 100644
--- a/src/test/ui/issues/issue-16538.thir.stderr
+++ b/src/test/ui/issues/issue-16538.thir.stderr
@@ -14,11 +14,13 @@ LL | static foo: &Y::X = &*Y::foo(Y::x as *const Y::X);
    |
    = note: extern statics are not controlled by the Rust type system: invalid data, aliasing violations or data races will cause undefined behavior
 
-error[E0015]: calls in statics are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `Y::foo` in statics
   --> $DIR/issue-16538.rs:15:23
    |
 LL | static foo: &Y::X = &*Y::foo(Y::x as *const Y::X);
    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: calls in statics are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/issues/issue-25901.rs b/src/test/ui/issues/issue-25901.rs
index a139ad0d3e3..ba12e1ad021 100644
--- a/src/test/ui/issues/issue-25901.rs
+++ b/src/test/ui/issues/issue-25901.rs
@@ -2,7 +2,7 @@ struct A;
 struct B;
 
 static S: &'static B = &A;
-//~^ ERROR calls in statics are limited to constant functions
+//~^ ERROR cannot perform deref coercion on `A` in statics
 
 use std::ops::Deref;
 
diff --git a/src/test/ui/issues/issue-25901.stderr b/src/test/ui/issues/issue-25901.stderr
index d6eb3760cdf..5c35250bc3f 100644
--- a/src/test/ui/issues/issue-25901.stderr
+++ b/src/test/ui/issues/issue-25901.stderr
@@ -1,8 +1,21 @@
-error[E0015]: calls in statics are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot perform deref coercion on `A` in statics
   --> $DIR/issue-25901.rs:4:24
    |
 LL | static S: &'static B = &A;
    |                        ^^
+   |
+   = note: attempting to deref into `B`
+note: deref defined here
+  --> $DIR/issue-25901.rs:10:5
+   |
+LL |     type Target = B;
+   |     ^^^^^^^^^^^^^^^^
+note: impl defined here, but it is not `const`
+  --> $DIR/issue-25901.rs:9:1
+   |
+LL | impl Deref for A {
+   | ^^^^^^^^^^^^^^^^
+   = note: calls in statics are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-39559-2.stderr b/src/test/ui/issues/issue-39559-2.stderr
index 3d765daa7cd..ea27e7bd250 100644
--- a/src/test/ui/issues/issue-39559-2.stderr
+++ b/src/test/ui/issues/issue-39559-2.stderr
@@ -1,14 +1,18 @@
-error[E0015]: calls in constants are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `<Dim3 as Dim>::dim` in constants
   --> $DIR/issue-39559-2.rs:14:24
    |
 LL |     let array: [usize; Dim3::dim()]
    |                        ^^^^^^^^^^^
+   |
+   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
 
-error[E0015]: calls in constants are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `<Dim3 as Dim>::dim` in constants
   --> $DIR/issue-39559-2.rs:16:15
    |
 LL |         = [0; Dim3::dim()];
    |               ^^^^^^^^^^^
+   |
+   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/never_type/issue-52443.rs b/src/test/ui/never_type/issue-52443.rs
index 4519833b864..cebcca944af 100644
--- a/src/test/ui/never_type/issue-52443.rs
+++ b/src/test/ui/never_type/issue-52443.rs
@@ -8,7 +8,7 @@ fn main() {
 
     [(); { for _ in 0usize.. {}; 0}];
     //~^ ERROR `for` is not allowed in a `const`
-    //~| ERROR calls in constants are limited to constant functions
+    //~| ERROR cannot convert
     //~| ERROR mutable references are not allowed in constants
-    //~| ERROR calls in constants are limited to constant functions
+    //~| ERROR cannot call non-const fn
 }
diff --git a/src/test/ui/never_type/issue-52443.stderr b/src/test/ui/never_type/issue-52443.stderr
index 216b56f7059..8c1755205f0 100644
--- a/src/test/ui/never_type/issue-52443.stderr
+++ b/src/test/ui/never_type/issue-52443.stderr
@@ -38,11 +38,18 @@ LL |     [(); loop { break }];
    |                 expected `usize`, found `()`
    |                 help: give it a value of the expected type: `break 42`
 
-error[E0015]: calls in constants are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot convert `RangeFrom<usize>` into an iterator in constants
   --> $DIR/issue-52443.rs:9:21
    |
 LL |     [(); { for _ in 0usize.. {}; 0}];
    |                     ^^^^^^^^
+   |
+note: impl defined here, but it is not `const`
+  --> $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL
+   |
+LL | impl<I: Iterator> IntoIterator for I {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
 
 error[E0658]: mutable references are not allowed in constants
   --> $DIR/issue-52443.rs:9:21
@@ -53,11 +60,13 @@ LL |     [(); { for _ in 0usize.. {}; 0}];
    = note: see issue #57349 <https://github.com/rust-lang/rust/issues/57349> for more information
    = help: add `#![feature(const_mut_refs)]` to the crate attributes to enable
 
-error[E0015]: calls in constants are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `<RangeFrom<usize> as Iterator>::next` in constants
   --> $DIR/issue-52443.rs:9:21
    |
 LL |     [(); { for _ in 0usize.. {}; 0}];
    |                     ^^^^^^^^
+   |
+   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to 6 previous errors; 1 warning emitted
 
diff --git a/src/test/ui/rfc-2632-const-trait-impl/call-const-trait-method-fail.rs b/src/test/ui/rfc-2632-const-trait-impl/call-const-trait-method-fail.rs
index 33e839fd120..5f55d61f5fd 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/call-const-trait-method-fail.rs
+++ b/src/test/ui/rfc-2632-const-trait-impl/call-const-trait-method-fail.rs
@@ -22,7 +22,7 @@ pub const fn add_i32(a: i32, b: i32) -> i32 {
 
 pub const fn add_u32(a: u32, b: u32) -> u32 {
     a.plus(b)
-    //~^ ERROR calls in constant functions are limited to constant functions
+    //~^ ERROR cannot call non-const fn
 }
 
 fn main() {}
diff --git a/src/test/ui/rfc-2632-const-trait-impl/call-const-trait-method-fail.stderr b/src/test/ui/rfc-2632-const-trait-impl/call-const-trait-method-fail.stderr
index 5a73c4debb4..b5680c04a65 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/call-const-trait-method-fail.stderr
+++ b/src/test/ui/rfc-2632-const-trait-impl/call-const-trait-method-fail.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
-  --> $DIR/call-const-trait-method-fail.rs:24:5
+error[E0015]: cannot call non-const fn `<u32 as Plus>::plus` in constant functions
+  --> $DIR/call-const-trait-method-fail.rs:24:7
    |
 LL |     a.plus(b)
-   |     ^^^^^^^^^
+   |       ^^^^^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/rfc-2632-const-trait-impl/call-generic-method-fail.rs b/src/test/ui/rfc-2632-const-trait-impl/call-generic-method-fail.rs
index e96249ff2fd..e3de75ea519 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/call-generic-method-fail.rs
+++ b/src/test/ui/rfc-2632-const-trait-impl/call-generic-method-fail.rs
@@ -3,7 +3,7 @@
 
 pub const fn equals_self<T: PartialEq>(t: &T) -> bool {
     *t == *t
-    //~^ ERROR calls in constant functions are limited to constant functions
+    //~^ ERROR cannot call non-const operator
 }
 
 fn main() {}
diff --git a/src/test/ui/rfc-2632-const-trait-impl/call-generic-method-fail.stderr b/src/test/ui/rfc-2632-const-trait-impl/call-generic-method-fail.stderr
index 818c5828696..d50100d033e 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/call-generic-method-fail.stderr
+++ b/src/test/ui/rfc-2632-const-trait-impl/call-generic-method-fail.stderr
@@ -1,8 +1,14 @@
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const operator in constant functions
   --> $DIR/call-generic-method-fail.rs:5:5
    |
 LL |     *t == *t
    |     ^^^^^^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+help: consider further restricting this bound
+   |
+LL | pub const fn equals_self<T: PartialEq + ~const std::cmp::PartialEq>(t: &T) -> bool {
+   |                                       ++++++++++++++++++++++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/rfc-2632-const-trait-impl/const-check-fns-in-const-impl.rs b/src/test/ui/rfc-2632-const-trait-impl/const-check-fns-in-const-impl.rs
index 3a707416352..b3e3dd62be8 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/const-check-fns-in-const-impl.rs
+++ b/src/test/ui/rfc-2632-const-trait-impl/const-check-fns-in-const-impl.rs
@@ -9,7 +9,7 @@ fn non_const() {}
 
 impl const T for S {
     fn foo() { non_const() }
-    //~^ ERROR calls in constant functions
+    //~^ ERROR cannot call non-const fn
 }
 
 fn main() {}
diff --git a/src/test/ui/rfc-2632-const-trait-impl/const-check-fns-in-const-impl.stderr b/src/test/ui/rfc-2632-const-trait-impl/const-check-fns-in-const-impl.stderr
index aaec67161a6..9e49785c589 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/const-check-fns-in-const-impl.stderr
+++ b/src/test/ui/rfc-2632-const-trait-impl/const-check-fns-in-const-impl.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `non_const` in constant functions
   --> $DIR/const-check-fns-in-const-impl.rs:11:16
    |
 LL |     fn foo() { non_const() }
    |                ^^^^^^^^^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/rfc-2632-const-trait-impl/const-default-method-bodies.rs b/src/test/ui/rfc-2632-const-trait-impl/const-default-method-bodies.rs
index 7a0db9c98ea..4b685b3b2b7 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/const-default-method-bodies.rs
+++ b/src/test/ui/rfc-2632-const-trait-impl/const-default-method-bodies.rs
@@ -23,7 +23,7 @@ impl const ConstDefaultFn for ConstImpl {
 
 const fn test() {
     NonConstImpl.a();
-    //~^ ERROR calls in constant functions are limited to constant functions, tuple structs and tuple variants
+    //~^ ERROR cannot call non-const fn
     ConstImpl.a();
 }
 
diff --git a/src/test/ui/rfc-2632-const-trait-impl/const-default-method-bodies.stderr b/src/test/ui/rfc-2632-const-trait-impl/const-default-method-bodies.stderr
index 63e4095af29..853fa3d6478 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/const-default-method-bodies.stderr
+++ b/src/test/ui/rfc-2632-const-trait-impl/const-default-method-bodies.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
-  --> $DIR/const-default-method-bodies.rs:25:5
+error[E0015]: cannot call non-const fn `<NonConstImpl as ConstDefaultFn>::a` in constant functions
+  --> $DIR/const-default-method-bodies.rs:25:18
    |
 LL |     NonConstImpl.a();
-   |     ^^^^^^^^^^^^^^^^
+   |                  ^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/rfc-2632-const-trait-impl/cross-crate.gated.stderr b/src/test/ui/rfc-2632-const-trait-impl/cross-crate.gated.stderr
index 3f553a8ee70..df960902133 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/cross-crate.gated.stderr
+++ b/src/test/ui/rfc-2632-const-trait-impl/cross-crate.gated.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
-  --> $DIR/cross-crate.rs:15:5
+error[E0015]: cannot call non-const fn `<cross_crate::NonConst as cross_crate::MyTrait>::func` in constant functions
+  --> $DIR/cross-crate.rs:15:14
    |
 LL |     NonConst.func();
-   |     ^^^^^^^^^^^^^^^
+   |              ^^^^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/rfc-2632-const-trait-impl/cross-crate.rs b/src/test/ui/rfc-2632-const-trait-impl/cross-crate.rs
index 4bd3359947d..670d06b85f2 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/cross-crate.rs
+++ b/src/test/ui/rfc-2632-const-trait-impl/cross-crate.rs
@@ -13,9 +13,9 @@ fn non_const_context() {
 
 const fn const_context() {
     NonConst.func();
-    //~^ ERROR: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+    //~^ ERROR: cannot call non-const fn
     Const.func();
-    //[stock]~^ ERROR: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+    //[stock]~^ ERROR: cannot call non-const fn
 }
 
 fn main() {}
diff --git a/src/test/ui/rfc-2632-const-trait-impl/cross-crate.stock.stderr b/src/test/ui/rfc-2632-const-trait-impl/cross-crate.stock.stderr
index 9908f47a7b2..ea75ad0aeaf 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/cross-crate.stock.stderr
+++ b/src/test/ui/rfc-2632-const-trait-impl/cross-crate.stock.stderr
@@ -1,14 +1,18 @@
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
-  --> $DIR/cross-crate.rs:15:5
+error[E0015]: cannot call non-const fn `<cross_crate::NonConst as cross_crate::MyTrait>::func` in constant functions
+  --> $DIR/cross-crate.rs:15:14
    |
 LL |     NonConst.func();
-   |     ^^^^^^^^^^^^^^^
+   |              ^^^^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
-  --> $DIR/cross-crate.rs:17:5
+error[E0015]: cannot call non-const fn `<cross_crate::Const as cross_crate::MyTrait>::func` in constant functions
+  --> $DIR/cross-crate.rs:17:11
    |
 LL |     Const.func();
-   |     ^^^^^^^^^^^^
+   |           ^^^^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/rfc-2632-const-trait-impl/issue-88155.rs b/src/test/ui/rfc-2632-const-trait-impl/issue-88155.rs
index 157005bba7b..e4fc65e3cb3 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/issue-88155.rs
+++ b/src/test/ui/rfc-2632-const-trait-impl/issue-88155.rs
@@ -7,7 +7,7 @@ pub trait A {
 
 pub const fn foo<T: A>() -> bool {
     T::assoc()
-    //~^ ERROR calls in constant functions are limited
+    //~^ ERROR cannot call non-const fn
 }
 
 fn main() {}
diff --git a/src/test/ui/rfc-2632-const-trait-impl/issue-88155.stderr b/src/test/ui/rfc-2632-const-trait-impl/issue-88155.stderr
index 931baac5389..b94d655a9ff 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/issue-88155.stderr
+++ b/src/test/ui/rfc-2632-const-trait-impl/issue-88155.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `<T as A>::assoc` in constant functions
   --> $DIR/issue-88155.rs:9:5
    |
 LL |     T::assoc()
    |     ^^^^^^^^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/rfc-2632-const-trait-impl/std-impl-gate.rs b/src/test/ui/rfc-2632-const-trait-impl/std-impl-gate.rs
index c6975da7121..2f54c09e31c 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/std-impl-gate.rs
+++ b/src/test/ui/rfc-2632-const-trait-impl/std-impl-gate.rs
@@ -11,7 +11,7 @@ fn non_const_context() -> Vec<usize> {
 
 const fn const_context() -> Vec<usize> {
     Default::default()
-    //[stock]~^ ERROR calls in constant functions are limited
+    //[stock]~^ ERROR cannot call non-const fn
 }
 
 fn main() {
diff --git a/src/test/ui/rfc-2632-const-trait-impl/std-impl-gate.stock.stderr b/src/test/ui/rfc-2632-const-trait-impl/std-impl-gate.stock.stderr
index 55a0daaaec7..0b450a94742 100644
--- a/src/test/ui/rfc-2632-const-trait-impl/std-impl-gate.stock.stderr
+++ b/src/test/ui/rfc-2632-const-trait-impl/std-impl-gate.stock.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `<Vec<usize> as Default>::default` in constant functions
   --> $DIR/std-impl-gate.rs:13:5
    |
 LL |     Default::default()
    |     ^^^^^^^^^^^^^^^^^^
+   |
+   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/static/static-vec-repeat-not-constant.stderr b/src/test/ui/static/static-vec-repeat-not-constant.stderr
index ef98aa546eb..84fc638a973 100644
--- a/src/test/ui/static/static-vec-repeat-not-constant.stderr
+++ b/src/test/ui/static/static-vec-repeat-not-constant.stderr
@@ -1,8 +1,10 @@
-error[E0015]: calls in statics are limited to constant functions, tuple structs and tuple variants
+error[E0015]: cannot call non-const fn `foo` in statics
   --> $DIR/static-vec-repeat-not-constant.rs:3:25
    |
 LL | static a: [isize; 2] = [foo(); 2];
    |                         ^^^^^
+   |
+   = note: calls in statics are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to previous error