FTBFS with "repository '/amnesia.git/.git/modules/submodules/aufs4-standalone' does not exist"

Today when I tried to build devel it failed with

+ git clone --shared /amnesia.git/.git/modules/submodules/aufs4-standalone
fatal: repository '/amnesia.git/.git/modules/submodules/aufs4-standalone' does not exist

I was able to fix it by changing the permission of the submodules directories and the parent directories from 700 to 755:

chmod 755 .git/modules .git/modules/submodules .git/modules/submodules/*

This seems to be caused by df8a338ea6e078113ef6a03d7e3fbb3ffc7467d1. We should somehow make sure that the vagrant user actually has read access to the submodules directory. I don’t know why it had permission 700 on my system.

Related issues

Related to #16476 (closed)
Blocks #16209

Original created by @segfault on 16607 (Redmine)

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information