+
+# Unbound variable in thunked field.
+cat > "$module_dir/foo.scm" <<EOF
+(define-module (foo)
+ #:use-module (guix tests)
+ #:use-module (guix build-system trivial))
+
+(define-public foo
+ (dummy-package "package-with-something-wrong"
+ (build-system trivial-build-system)
+ (inputs (quasiquote (("sed" ,sed)))))) ;unbound variable
+EOF
+
+if guix build package-with-something-wrong -n; then false; else true; fi
+guix build package-with-something-wrong -n 2> "$module_dir/err" || true
+grep "unbound" "$module_dir/err" # actual error
+grep "forget.*(gnu packages base)" "$module_dir/err" # hint
+
+# Unbound variable at the top level.
+cat > "$module_dir/foo.scm" <<EOF
+(define-module (foo)
+ #:use-module (guix tests))
+
+(define-public foo
+ (dummy-package "package-with-something-wrong"
+ (build-system gnu-build-system))) ;unbound variable
+EOF
+
+guix build sed -n 2> "$module_dir/err"
+grep "unbound" "$module_dir/err" # actual error
+grep "forget.*(guix build-system gnu)" "$module_dir/err" # hint
+
+rm -f "$module_dir"/*
+
+# Wrong 'define-module' clause reported by 'warn-about-load-error'.
+cat > "$module_dir/foo.scm" <<EOF
+(define-module (something foo)
+ #:use-module (guix)
+ #:use-module (gnu))
+EOF
+guix build guile-bootstrap -n 2> "$module_dir/err"
+grep "does not match file name" "$module_dir/err"
+
+rm "$module_dir"/*
+