[configure] Add failsafe for missing submodules (mono/mono#13957)
authorAlexander Köplinger <alex.koeplinger@outlook.com>
Wed, 10 Apr 2019 13:26:28 +0000 (15:26 +0200)
committerGitHub <noreply@github.com>
Wed, 10 Apr 2019 13:26:28 +0000 (15:26 +0200)
commit5e0a3b97ccd92a99d9e9ea13904fabc2dc583c0e
treeaa5c6bb797d0d2e5fafa6cc0528a6bd772435441
parent7b7f91a6e72901620d66bf16e291143643c888d2
[configure] Add failsafe for missing submodules (mono/mono#13957)

GitHub provides a way to download a .zip/.tar.gz of the repository content in their UI, however the archive doesn't contain git submodules.

The mono build then fails with confusing "missing file" errors.

Since GitHub doesn't let us disable the archive download we should at least add some logic to detect this broken case and bail out.

Commit migrated from https://github.com/mono/mono/commit/e8caaa1dbd880767bcf07ccfa8b9f695377ddd8d
src/mono/Makefile.am