check that files are executable in finding executables.

[tatome]

conda build got hung up on a file called git in my $PATH that was not executable (by me). This fixes it.

[msarahan]

Cool, thanks. Do you know how this behaves on Windows? Is this worth adding a test for, so that future work doesn't break it?

[tatome]

It probably makes as much sense on Windows as on *nix to check whether a file with the correct name is actually executable, but I don't have access to a Windows machine, so I can't test that.

That's a good point about the regression test, though. I'll see what I can do. Is it OK if I make the test conditional on the OS?

[tatome]

OK, I wrote a test for find_executable.

Since I can't test on Windows, I'm not changing the code for win32 in find_executable and the test does nothing if on that architecture. Someone else with access to a Windows machine could fix find_executable and enable the test for win32.

[msarahan]

Great, thanks! I'll test on windows when I can. Nice test!

The Travis failure looks like a fluke, so I'm going to merge this.

[github-actions]

Hi there, thank you for your contribution!

This pull request has been automatically locked because it has not had recent activity after being closed.

Please open a new issue or pull request if needed.

Thanks!