Issue #3241318 by alexpott:...

    // executable script named 'git' that always exits with 127, as if git were

    // not found. Note that we run our tests using process isolation, so we do

    // not need to restore the PATH when we are done.

    $unavailableGitPath = $this->fixtures->binFixtureDir('disable-git-bin');

    $unavailableGitPath = $sut . '/bin';

    mkdir($unavailableGitPath);

    $bash = <<<SH

#!/bin/bash

exit 127

SH;

    file_put_contents($unavailableGitPath . '/git', $bash);

    chmod($unavailableGitPath . '/git', 0755);

    $oldPath = getenv('PATH');

    putenv('PATH=' . $unavailableGitPath . ':' . getenv('PATH'));

#!/bin/bash

exit 127