qemu build issues

[mehdilauters]

Hello, thank you for this good idea to spead up cross compilation!
I am trying to build it but I get into errors around the qemu build.

If I clone your repo and directly start the build.sh script, qemu fail to build as the submodule is not initialized (maybe it should be a good idea to do it on the script?).

When I initilize the first level submodules with git submodule update --init, I then get the following error when building:

Setting up libalgorithm-merge-perl (0.08-3) ...
Setting up libglib2.0-dev:amd64 (2.58.3-2+deb10u3) ...
Processing triggers for libc-bin (2.28-10) ...
Processing triggers for ca-certificates (20200601~deb10u2) ...
Updating certificates in /etc/ssl/certs...
0 added, 0 removed; done.
Running hooks in /etc/ca-certificates/update.d...
done.
warn: ignoring non-existent submodule ui/keycodemapdb
warn: ignoring non-existent submodule meson
warn: ignoring non-existent submodule tests/fp/berkeley-testfloat-3
warn: ignoring non-existent submodule tests/fp/berkeley-softfloat-3
warn: ignoring non-existent submodule dtc
warn: ignoring non-existent submodule capstone
warn: ignoring non-existent submodule slirp
fatal: not a git repository: /root/qemu-src/../.git/modules/qemu
/root/qemu-src/scripts/git-submodule.sh: failed to update modules

Unable to automatically checkout GIT submodules ''.
If you require use of an alternative GIT binary (for example to
enable use of a transparent proxy), then please specify it by
running configure by with the '--with-git' argument. e.g.

 $ ./configure --with-git='tsocks git'

Alternatively you may disable automatic GIT submodule checkout
with:

 $ ./configure --with-git-submodules=validate

and then manually update submodules prior to running make, with:

 $ scripts/git-submodule.sh update 

make: *** No rule to make target 'install'.  Stop.
could not find file /media/mehdi/c771bf9e-241c-4231-b0d9-0503e1297eb1/workdir/qemu-install/bin/qemu-aarch64 after build

If I initialize recursively all modules with git submodule update --init --recursive I get the same error as previously

It is not a network issue has I tried to ping google.com from the build script to check it.

Thank you for your help