Missing error checking that Process(...) actually worked

[ValtsS]

composer/src/Composer/Util/ProcessExecutor.php

Line 261 in 9113621

$job['process'] = $process;

if process(..) failed then it fails down the line when tries to references job['process'] and does not find the key. Experienced on a PHP installation where certain functions are disabled.

[Seldaek]

I am not really sure how to reproduce the failure so am not 100% sure the fix is correct, but if you can check with the latest snapshot (composer self-update --snapshot) that would be great.

[ValtsS]

Seems to have worked: