tests.trivial-builders.overriding: update after shellDryRun

pkgs/build-support/trivial-builders.nix

@@ -121,18 +121,18 @@ rec {
         allowSubstitutes = false;
       }
       ''
-        n=$out${destination}
-        mkdir -p "$(dirname "$n")"
+        target=$out${destination}
+        mkdir -p "$(dirname "$target")"
 
         if [ -e "$textPath" ]; then
-          mv "$textPath" "$n"
+          mv "$textPath" "$target"
         else
-          echo -n "$text" > "$n"
+          echo -n "$text" > "$target"
         fi
 
         eval "$checkPhase"
 
-        (test -n "$executable" && chmod +x "$n") || true
+        (test -n "$executable" && chmod +x "$target") || true
       '';
 
   /*
@@ -219,7 +219,7 @@ rec {
         ${text}
         '';
       checkPhase = ''
-        ${stdenv.shellDryRun} $out
+        ${stdenv.shellDryRun} "$target"
       '';
     };
 
@@ -246,7 +246,7 @@ rec {
         ${text}
         '';
       checkPhase = ''
-        ${stdenv.shellDryRun} $out/bin/${name}
+        ${stdenv.shellDryRun} "$target"
       '';
     };
 
@@ -295,8 +295,8 @@ rec {
       checkPhase =
         if checkPhase == null then ''
           runHook preCheck
-          ${stdenv.shellDryRun} $out/bin/${name}
-          ${shellcheck}/bin/shellcheck $out/bin/${name}
+          ${stdenv.shellDryRun} "$target"
+          ${shellcheck}/bin/shellcheck "$target"
           runHook postCheck
         ''
         else checkPhase;

pkgs/build-support/trivial-builders/test-overriding.nix

@@ -1,10 +1,11 @@
 # Check that overriding works for trivial-builders like
 # `writeShellScript` via `overrideAttrs`. This is useful
-# to override the `checkPhase`, e. g. when you want
-# to enable extglob in `writeShellScript`.
+# to override the `checkPhase`, e. g. if you want
+# to disable extglob in `writeShellScript`.
 #
-# Run using `nix-build -A tests.trivial-overriding`.
+# Run using `nix-build -A tests.trivial-builders.overriding`.
 { lib
+, stdenv
 , runtimeShell
 , runCommand
 , callPackage
@@ -21,33 +22,6 @@ let
     rm success
   '';
 
-  # Reuse the old `checkPhase` of `writeShellScript`, but enable extglob.
-  allowExtglob = old: {
-    checkPhase = ''
-      # make sure we don't change the settings for
-      # the rest of the derivation's build
-      (
-        export BASHOPTS
-        shopt -s extglob
-        ${old.checkPhase}
-      )
-    '';
-  };
-
-  # Run old checkPhase, but only succeed if it fails.
-  # This HACK is required because we can't introspect build failures
-  # in nix: With `assertFail` we want to make sure that the default
-  # `checkPhase` would fail if extglob was used in the script.
-  assertFail = old: {
-    # write old checkPhase into a shell script, so we can check for
-    # the phase to fail even though we have `set -e`.
-    checkPhase = ''
-      if source ${writeShellScript "old-check-phase" old.checkPhase} 2>/dev/null; then
-        exit 1
-      fi
-    '';
-  };
-
   simpleCase = case:
     writeShellScript "test-trivial-overriding-${case}" extglobScript;
 
@@ -70,16 +44,33 @@ let
     executable = true;
   };
 
-  mkCase = f: type: isBin:
+    disallowExtglob = x: x.overrideAttrs (_: {
+      checkPhase = ''
+        ${stdenv.shell} -n "$target"
+      '';
+    });
+
+    # Run old checkPhase, but only succeed if it fails.
+    # This HACK is required because we can't introspect build failures
+    # in nix: With `assertFail` we want to make sure that the default
+    # `checkPhase` would fail if extglob was used in the script.
+    assertFail = x: x.overrideAttrs (old: {
+      checkPhase = ''
+        if
+          ${old.checkPhase}
+        then exit 1; fi
+      '';
+    });
+
+  mkCase = case: outcome: isBin:
     let
-      drv = (f type).overrideAttrs
-        (if type == "succ" then allowExtglob else assertFail);
+      drv = lib.pipe outcome ([ case ] ++ lib.optionals (outcome == "fail") [ disallowExtglob assertFail ]);
     in if isBin then "${drv}/bin/${drv.name}" else drv;
 
   writeTextOverrides = {
-    # Enabling globbing in checkPhase
+    # Make sure extglob works by default
     simpleSucc = mkCase simpleCase "succ" false;
-    # Ensure it's possible to fail; in this case globbing is not enabled.
+    # Ensure it's possible to fail; in this case extglob is not enabled
     simpleFail = mkCase simpleCase "fail" false;
     # Do the same checks after wrapping with callPackage
     # to make sure callPackage doesn't mess with the override
@@ -103,7 +94,7 @@ let
       name = script.name or (builtins.baseNameOf script);
     in writeShellScript "run-${name}" ''
       if [ "$(${script})" != "success" ]; then
-        echo "Failed in ${script}"
+        echo "Failed in ${name}"
         exit 1
       fi
     '';