diff --git a/Cargo.lock b/Cargo.lock
index 58d95f927bf..ba8b2c27005 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3627,7 +3627,6 @@ dependencies = [
  "rustc_macros",
  "rustc_serialize",
  "rustc_span",
- "smallvec",
 ]
 
 [[package]]
@@ -3708,7 +3707,6 @@ dependencies = [
  "icu_locid",
  "icu_locid_transform",
  "icu_provider",
- "icu_provider_adapters",
  "zerovec",
 ]
 
@@ -3889,7 +3887,6 @@ dependencies = [
  "portable-atomic",
  "rustc-hash",
  "rustc-rayon",
- "rustc-rayon-core",
  "rustc_arena",
  "rustc_graphviz",
  "rustc_index",
@@ -3930,7 +3927,6 @@ dependencies = [
  "rustc_expand",
  "rustc_feature",
  "rustc_fluent_macro",
- "rustc_hir",
  "rustc_hir_analysis",
  "rustc_hir_pretty",
  "rustc_hir_typeck",
@@ -4193,7 +4189,6 @@ dependencies = [
  "proc-macro2",
  "quote",
  "syn 2.0.66",
- "synstructure",
 ]
 
 [[package]]
@@ -4385,7 +4380,6 @@ dependencies = [
  "field-offset",
  "gsgdt",
  "polonius-engine",
- "rustc-rayon",
  "rustc-rayon-core",
  "rustc_apfloat",
  "rustc_arena",
@@ -4417,7 +4411,6 @@ dependencies = [
 name = "rustc_mir_build"
 version = "0.0.0"
 dependencies = [
- "either",
  "itertools 0.12.1",
  "rustc_apfloat",
  "rustc_arena",
@@ -4436,7 +4429,6 @@ dependencies = [
  "rustc_span",
  "rustc_target",
  "rustc_trait_selection",
- "smallvec",
  "tracing",
 ]
 
@@ -4511,14 +4503,7 @@ dependencies = [
 name = "rustc_next_trait_solver"
 version = "0.0.0"
 dependencies = [
- "derivative",
- "rustc_ast_ir",
- "rustc_data_structures",
- "rustc_macros",
- "rustc_serialize",
  "rustc_type_ir",
- "rustc_type_ir_macros",
- "tracing",
 ]
 
 [[package]]
@@ -4623,7 +4608,6 @@ version = "0.0.0"
 dependencies = [
  "field-offset",
  "measureme",
- "rustc-rayon-core",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_hir",
@@ -5329,7 +5313,6 @@ name = "stable_mir"
 version = "0.1.0-preview"
 dependencies = [
  "scoped-tls",
- "tracing",
 ]
 
 [[package]]
@@ -5625,8 +5608,6 @@ dependencies = [
  "core",
  "getopts",
  "libc",
- "panic_abort",
- "panic_unwind",
  "std",
 ]
 
diff --git a/compiler/rustc_ast_ir/Cargo.toml b/compiler/rustc_ast_ir/Cargo.toml
index e761b7adad3..a78c91e0615 100644
--- a/compiler/rustc_ast_ir/Cargo.toml
+++ b/compiler/rustc_ast_ir/Cargo.toml
@@ -9,7 +9,6 @@ rustc_data_structures = { path = "../rustc_data_structures", optional = true }
 rustc_macros = { path = "../rustc_macros", optional = true }
 rustc_serialize = { path = "../rustc_serialize", optional = true }
 rustc_span = { path = "../rustc_span", optional = true }
-smallvec = { version = "1.8.1" }
 # tidy-alphabetical-end
 
 [features]
diff --git a/compiler/rustc_baked_icu_data/Cargo.toml b/compiler/rustc_baked_icu_data/Cargo.toml
index 48af4e6f600..e6cfb4887c9 100644
--- a/compiler/rustc_baked_icu_data/Cargo.toml
+++ b/compiler/rustc_baked_icu_data/Cargo.toml
@@ -9,7 +9,6 @@ icu_list = "1.2"
 icu_locid = "1.2"
 icu_locid_transform = "1.3.2"
 icu_provider = "1.2"
-icu_provider_adapters = "1.2"
 zerovec = "0.10.0"
 # tidy-alphabetical-end
 
diff --git a/compiler/rustc_data_structures/Cargo.toml b/compiler/rustc_data_structures/Cargo.toml
index 2b61e17efa2..6876046a583 100644
--- a/compiler/rustc_data_structures/Cargo.toml
+++ b/compiler/rustc_data_structures/Cargo.toml
@@ -16,7 +16,6 @@ libc = "0.2"
 measureme = "11"
 rustc-hash = "1.1.0"
 rustc-rayon = { version = "0.5.0", optional = true }
-rustc-rayon-core = { version = "0.5.0", optional = true }
 rustc_arena = { path = "../rustc_arena" }
 rustc_graphviz = { path = "../rustc_graphviz" }
 rustc_index = { path = "../rustc_index", package = "rustc_index" }
@@ -52,5 +51,5 @@ portable-atomic = "1.5.1"
 
 [features]
 # tidy-alphabetical-start
-rustc_use_parallel_compiler = ["indexmap/rustc-rayon", "rustc-rayon", "rustc-rayon-core"]
+rustc_use_parallel_compiler = ["indexmap/rustc-rayon", "rustc-rayon"]
 # tidy-alphabetical-end
diff --git a/compiler/rustc_driver_impl/Cargo.toml b/compiler/rustc_driver_impl/Cargo.toml
index 5f7504add8d..91cbffcd707 100644
--- a/compiler/rustc_driver_impl/Cargo.toml
+++ b/compiler/rustc_driver_impl/Cargo.toml
@@ -19,7 +19,6 @@ rustc_errors = { path = "../rustc_errors" }
 rustc_expand = { path = "../rustc_expand" }
 rustc_feature = { path = "../rustc_feature" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }
-rustc_hir = { path = "../rustc_hir" }
 rustc_hir_analysis = { path = "../rustc_hir_analysis" }
 rustc_hir_pretty = { path = "../rustc_hir_pretty" }
 rustc_hir_typeck = { path = "../rustc_hir_typeck" }
diff --git a/compiler/rustc_index_macros/Cargo.toml b/compiler/rustc_index_macros/Cargo.toml
index c4ca29db3c2..07ee81788ce 100644
--- a/compiler/rustc_index_macros/Cargo.toml
+++ b/compiler/rustc_index_macros/Cargo.toml
@@ -7,11 +7,10 @@ edition = "2021"
 proc-macro = true
 
 [dependencies]
-synstructure = "0.13.0"
 syn = { version = "2.0.9", features = ["full"] }
 proc-macro2 = "1"
 quote = "1"
 
 [features]
 default = ["nightly"]
-nightly = []
\ No newline at end of file
+nightly = []
diff --git a/compiler/rustc_middle/Cargo.toml b/compiler/rustc_middle/Cargo.toml
index d1cdabc293d..3dc592980fd 100644
--- a/compiler/rustc_middle/Cargo.toml
+++ b/compiler/rustc_middle/Cargo.toml
@@ -11,7 +11,6 @@ either = "1.5.0"
 field-offset = "0.3.5"
 gsgdt = "0.1.2"
 polonius-engine = "0.13.0"
-rustc-rayon = { version = "0.5.0", optional = true }
 rustc-rayon-core = { version = "0.5.0", optional = true }
 rustc_apfloat = "0.2.0"
 rustc_arena = { path = "../rustc_arena" }
@@ -41,5 +40,5 @@ tracing = "0.1"
 
 [features]
 # tidy-alphabetical-start
-rustc_use_parallel_compiler = ["rustc-rayon", "rustc-rayon-core"]
+rustc_use_parallel_compiler = ["rustc-rayon-core"]
 # tidy-alphabetical-end
diff --git a/compiler/rustc_mir_build/Cargo.toml b/compiler/rustc_mir_build/Cargo.toml
index 77f27236437..5d828d0093f 100644
--- a/compiler/rustc_mir_build/Cargo.toml
+++ b/compiler/rustc_mir_build/Cargo.toml
@@ -5,7 +5,6 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
-either = "1"
 itertools = "0.12"
 rustc_apfloat = "0.2.0"
 rustc_arena = { path = "../rustc_arena" }
@@ -24,6 +23,5 @@ rustc_session = { path = "../rustc_session" }
 rustc_span = { path = "../rustc_span" }
 rustc_target = { path = "../rustc_target" }
 rustc_trait_selection = { path = "../rustc_trait_selection" }
-smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 tracing = "0.1"
 # tidy-alphabetical-end
diff --git a/compiler/rustc_next_trait_solver/Cargo.toml b/compiler/rustc_next_trait_solver/Cargo.toml
index c30d21fd784..50dbc991f8f 100644
--- a/compiler/rustc_next_trait_solver/Cargo.toml
+++ b/compiler/rustc_next_trait_solver/Cargo.toml
@@ -5,22 +5,9 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
-derivative = "2.2.0"
-rustc_ast_ir = { path = "../rustc_ast_ir", default-features = false }
-rustc_data_structures = { path = "../rustc_data_structures", optional = true }
-rustc_macros = { path = "../rustc_macros", optional = true }
-rustc_serialize = { path = "../rustc_serialize", optional = true }
 rustc_type_ir = { path = "../rustc_type_ir", default-features = false }
-rustc_type_ir_macros = { path = "../rustc_type_ir_macros" }
-tracing = "0.1"
 # tidy-alphabetical-end
 
 [features]
 default = ["nightly"]
-nightly = [
-    "rustc_type_ir/nightly",
-    "rustc_macros",
-    "rustc_serialize",
-    "rustc_data_structures",
-    "rustc_ast_ir/nightly",
-]
+nightly = ["rustc_type_ir/nightly"]
diff --git a/compiler/rustc_query_impl/Cargo.toml b/compiler/rustc_query_impl/Cargo.toml
index c57f22a0da2..2bb1be22b98 100644
--- a/compiler/rustc_query_impl/Cargo.toml
+++ b/compiler/rustc_query_impl/Cargo.toml
@@ -7,7 +7,6 @@ edition = "2021"
 # tidy-alphabetical-start
 field-offset = "0.3.5"
 measureme = "11"
-rustc-rayon-core = { version = "0.5.0", optional = true }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_hir = { path = "../rustc_hir" }
@@ -23,5 +22,5 @@ tracing = "0.1"
 
 [features]
 # tidy-alphabetical-start
-rustc_use_parallel_compiler = ["rustc-rayon-core", "rustc_query_system/rustc_use_parallel_compiler"]
+rustc_use_parallel_compiler = ["rustc_query_system/rustc_use_parallel_compiler"]
 # tidy-alphabetical-end
diff --git a/compiler/stable_mir/Cargo.toml b/compiler/stable_mir/Cargo.toml
index c61e217bf9f..4ed61152736 100644
--- a/compiler/stable_mir/Cargo.toml
+++ b/compiler/stable_mir/Cargo.toml
@@ -4,5 +4,4 @@ version = "0.1.0-preview"
 edition = "2021"
 
 [dependencies]
-tracing = "0.1"
 scoped-tls = "1.0"
diff --git a/library/test/Cargo.toml b/library/test/Cargo.toml
index 0e2409f63ab..75cc7c00e38 100644
--- a/library/test/Cargo.toml
+++ b/library/test/Cargo.toml
@@ -7,8 +7,6 @@ edition = "2021"
 getopts = { version = "0.2.21", features = ['rustc-dep-of-std'] }
 std = { path = "../std" }
 core = { path = "../core" }
-panic_unwind = { path = "../panic_unwind" }
-panic_abort = { path = "../panic_abort" }
 
 [target.'cfg(not(all(windows, target_env = "msvc")))'.dependencies]
 libc = { version = "0.2.150", default-features = false }