rewrite jobserver-error to rmake

Author: Oneirical

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -7,7 +7,6 @@ run-make/emit-to-stdout/Makefile
 run-make/extern-fn-reachable/Makefile
 run-make/incr-add-rust-src-component/Makefile
 run-make/issue-84395-lto-embed-bitcode/Makefile
-run-make/jobserver-error/Makefile
 run-make/libs-through-symlinks/Makefile
 run-make/libtest-json/Makefile
 run-make/libtest-junit/Makefile

tests/run-make/jobserver-error/Makefile

@@ -0,0 +1,40 @@
+// If the environment variables contain an invalid `jobserver-auth`, this used
+// to cause an ICE (internal compiler error) until this was fixed in #109694.
+// Proper handling has been added, and this test checks that helpful warnings
+// and errors are printed instead in case of a wrong jobserver.
+// See https://github.com/rust-lang/rust/issues/46981
+
+// FIXME(Oneirical): The original test included this memo:
+// # Note that by default, the compiler uses file descriptors 0 (stdin), 1 (stdout), 2 (stderr),
+// # but also 3 and 4 for either end of the ctrl-c signal handler self-pipe.
+
+// FIXME(Oneirical): only-linux ignore-cross-compile
+
+use run_make_support::{diff, rfs, rustc};
+
+fn main() {
+    let out = rustc()
+        .stdin("fn main() {}")
+        .env("MAKEFLAGS", "--jobserver-auth=5,5")
+        .run_fail()
+        .stderr_utf8();
+    diff().expected_file("cannot_open_fd.stderr").actual_text("actual", out).run();
+    // FIXME(Oneirical): Find how to use file descriptor "3" with run-make-support
+    // and pipe /dev/null into it.
+    // Original lines:
+    //
+    // bash -c 'echo "fn main() {}" | makeflags="--jobserver-auth=3,3" $(rustc) - 3</dev/null' \
+    // 2>&1 | diff not_a_pipe.stderr -
+    // # this test randomly fails, see https://github.com/rust-lang/rust/issues/110321
+    // disabled:
+    // bash -c 'echo "fn main() {}" | makeflags="--jobserver-auth=3,3" $(rustc) - \
+    // 3< <(cat /dev/null)' 2>&1 | diff poisoned_pipe.stderr -
+    //
+    // let out = rustc()
+    //     .stdin("fn main() {}")
+    //     .input("-")
+    //     .env("MAKEFLAGS", "--jobserver-auth=0,0")
+    //     .run()
+    //     .stderr_utf8();
+    // diff().expected_file("not_a_pipe.stderr").actual_text("actual", out).run();
+}