make testbuild-android-armv7 stalls during sha256sum step
Suppose you don't have a testbuild directory containing any already built bundles. Now, start a build with
make testbuild-android-armv7 to get an .apk. The result is a stalled build in the release project.
The reason for that is that
sha256sum $(ls -1 *.exe *.tar.xz *.dmg *.mar *.zip *.tar.gz | grep -v '\.incremental\.mar$' | sort) > sha256sums-unsigned-build.txt
sha256sum > sha256sums-unsigned-build.txt
which waits for input. We have not been hitting that so far as both in the alpha and the nightly case other bundles in the directory are available. And for the mobile case legacy/trac#25164 (moved) is about to fix this as well. However, we might want to be a bit more conservative and only execute
sha256sum if we actually have an argument to pass. Otherwise this can lead to surprising results (like in this case).