llvm-project/clang/test/Frontend/output-paths.c

// RUN: not %clang_cc1 -emit-llvm -o %t.doesnotexist/somename %s 2> %t
// RUN: FileCheck -check-prefix=OUTPUTFAIL -DMSG=%errc_ENOENT -input-file=%t %s

// OUTPUTFAIL: error: unable to open output file '{{.*}}doesnotexist{{.}}somename': '[[MSG]]'