tests leave behind unremovable file.

[gbaz]

After resolving #97 (i think), running the tests for directory leaves a file that cannot be removed except by root.

This caused the hackage builder to stall for roughly a week because it was unable to remove the following file:

/home/builder/builder-dir/build-cache/tmp-install/directory-1.3.9.0/dist/test-RemovePathForcibly.tmp/removePathForcibly.tmp/f

It would be good if the test suite were fixed to avoid this issue.

[Rufflewind]

Were the tests interrupted or did any of them fail? Under normal circumstances, RemovePathForcibly.hs is supposed to remove f successfully and there are assertions to verify the removal.

[gbaz]

they failed but the available logs don't explain why -- https://hackage.haskell.org/package/directory-1.3.9.0/reports/1

i do think its bad practice for a failing test suite to leave a file that needs to be fixed by hand.

[gbaz]

Reran on the builder and here are some lines in the log that seem suspicious:

*** LongPaths: exception: yeah_its_longyeah_its_longyeah_its_longyeah_its_longyeah_its_longyeah_its_longyeah_its_longyeah_its_long: removePathForcibly:openFdAt: permission denied (Permission denied)

*** RemovePathForcibly: exception: f: removePathForcibly:openFdAt: permission denied (Permission denied)

The failures appear to be precisely that removePathForcibly does not work!

[hasufell]

Do you have more information on the system that this runs on?

[gbaz]

Indeed, I can't remove the created file by hand as the builder user even with rm -f -- I need to change to superuser to do it.

[gbaz]

Linux hackage-docbuilder 5.10.0-14-amd64 #1 SMP Debian 5.10.113-1 (2022-04-29) x86_64 with a nonsuperuser account.

[Rufflewind]

Turns out, the flag AT_SYMLINK_NOFOLLOW in fchmodat has inconsistent support among different permutations of kernels and C libraries. With this code,

directory/main.c

Lines 1 to 19 in dfe5e23

	#include <stdio.h>
	#include <fcntl.h> /* Definition of AT_* constants */
	#include <sys/stat.h>
	#include <errno.h>
	int main(void)
	{
	int dirfd = open(".", 0);
	if (dirfd < 0) {
	printf("open:errno = %d\n", errno);
	return 1;
	}
	if (fchmodat(dirfd, "main.c", 0777, AT_SYMLINK_NOFOLLOW) < 0) {
	printf("fchmodat:errno = %d\n", errno);
	return 1;
	}
	printf("OK\n");
	return 0;
	}

testing indicates that:

• It is supported on the macos-15 and ubuntu-24.04 images of GitHub Actions workers.
• It is unsupported on my WSL 2.6.3.0 (kernel 6.6.87.2-1) and fails with errno = 95 (EOPNOTSUPP).

This failure explains why removePathForcibly was unable to remove write-protected files on some systems, but cannot be reproduced on GitHub Actions workers.