[Test] t1901 - sparse checkout file when lock is taken fails (subtest 19)

Hi All,

This one has me confused. It fails 100% of the time on NonStop. The test looks reasonable, as do the messages. I am not certain that test_i18ngrep works properly - it falls down to the return 1 statement which causes the test to fail. The error message generated is "File already exists" not "File exists" as is required in the test. We should not be testing for specific text content originating from strerror - I thought we had this decision in a different thread. https://public-inbox.org/git/xmqq36intlpj.fsf@gitster-ct.c.googlers.com/

Thoughts?

expecting success of 1091.19 'fail when lock is taken':
        test_when_finished rm -rf repo/.git/info/sparse-checkout.lock &&
        touch repo/.git/info/sparse-checkout.lock &&
        test_must_fail git -C repo sparse-checkout set deep 2>err &&
        test_i18ngrep "File exists" err

error: 'grep File exists err' didn't find a match in: fatal: Unable to create '/home/ituglib/randall/git/t/trash directory.t1091-sparse-checkout-builtin/repo/.git/info/sparse-checkout.lock' : File already exists. <----- this is the test issue

Another git process seems to be running in this repository, e.g. an editor opened by 'git commit'. Please make sure all processes are terminated then try again. If it still fails, a git process may have crashed in this repository earlier: remove the file manually to continue. not ok 19 - fail when lock is taken # # test_when_finished rm -rf repo/.git/info/sparse-checkout.lock && # touch repo/.git/info/sparse-checkout.lock && # test_must_fail git -C repo sparse-checkout set deep 2>err && # test_i18ngrep "File exists" err #

Regards, Randall

-- Brief whoami:
 NonStop developer since approximately 211288444200000000
 UNIX developer since approximately 421664400
-- In my real life, I talk too much.

We grep for "File exists" in stderr of the failing `git sparse-checkout` to make sure that it failed for the right reason. We expect the string to show up there since we call `strerror(errno)` in `unable_to_lock_message()` in lockfile.c.

On the NonStop platform, this fails because the error string is "File already exists", which doesn't match our grepping.

See 9042140097 ("test-dir-iterator: do not assume errno values", 2019-07-30) for a somewhat similar fix. There, we patched a test helper, which meant we had access to `errno` and could investigate it better in the test helper instead of just outputting the numerical value and evaluating it in the test script. The current situation is different, since (short of modifying the lockfile machinery, e.g., to be more verbose) we don't have more than the output from `strerror()` available.

Except we do: We prefix `strerror(errno)` with `_("Unable to create '%s.lock': ")`. Let's grep for that part instead. It verifies that we were indeed unable to create the lock file. (If that fails for some other reason than the file existing, we really really should expect other tests to fail as well.)

An alternative fix would be to loosen the expression a bit and grep for "File.* exists" instead. There would be no guarantee that some other implementation couldn't come up with another error string, That is, that could be the first move in an endless game of whack-a-mole. Of course, it could also take us from "99" to "100" percent of the platforms and we'd never have this problem again. But since we have another way of addressing this, let's not even try the "loosen it up a bit" strategy.

Reported-by: Randall S. Becker <rsbecker@nexbridge.com>
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
---
 Hi Randall,

 Thanks for the report.

 > test to fail. The error message generated is "File already exists" not "File
 > exists" as is required in the test. We should not be testing for specific
 > text content originating from strerror - I thought we had this decision in a
 > different thread.
 > https://public-inbox.org/git/xmqq36intlpj.fsf@gitster-ct.c.googlers.com/

 > error: 'grep File exists err' didn't find a match in:
 > fatal: Unable to create '/home/ituglib/randall/git/t/trash
 > directory.t1091-sparse-checkout-builtin/repo/.git/info/sparse-checkout.lock'
 > : File already exists.   <----- this is the test issue

 Does this patch solve it?

 t/t1091-sparse-checkout-builtin.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

On 3/8/2020 4:46 AM, Martin Ågren wrote:

This is the better design, and I should have used it in the first place. The test is really trying to reveal that we are using a .lock file, and the new error message check makes this even more clear.

Your alternate substring is better than loosening the pattern in several ways.

I'll second the thanks on the report, and extra thanks to Martin for the fix!

This change looks good to me. The commit message is superb.

Thanks, -Stolee

Martin Ågren <martin.agren@gmail.com> writes:

Thanks for a quick fix. I agree that looking for our own string makes a lot more sense here.