Android CI is failing

[repi]

Our CI is failing on Android with:

Build WGPU example for Android
  Warning: You use environment variable ANDROID_HOME that is deprecated. Please, remove it and use ANDROID_SDK_ROOT instead. Now ANDROID_HOME is used
  Error: Android NDK is not found. Please set the path to the Android NDK with $ANDROID_NDK_ROOT environment variable.
  Error: Process completed with exit code 1.

Example: https://github.com/EmbarkStudios/rust-gpu/runs/7635577970?check_suite_focus=true

May be related to the following GitHub Action ubuntu image updates:

• [all OSs] Android NDK 21 will be replaced in favor of 25 on August, 1st actions/runner-images#5930
• [all OSs] Android ndk-bundle along with old NDK versions will be deprecated on July, 24 actions/runner-images#5879

[repi]

This is how we fixed it in the physx repo just now: EmbarkStudios/physx-rs#155

@eddyb can you try similar here, or @oisyn next week when back from vacation

[MarijnS95]

This is actions/runner-images#5879 (comment), ndk-bundle was deprecated and removed but these useful symlinks were removed by "accident" as well. Should be added back soon!

[eddyb]

This is how we fixed it in the physx repo just now: EmbarkStudios/physx-rs#155

That repo's CI seems to have been setting ANDROID_NDK_ROOT before, but here we didn't.

Hoping that the GHA fixes @MarijnS95 linked have already been propagated, I forced a re-run of the failing CI job, but before it can even get to the part where it uses the NDK, it now fails building cargo-apk because libc 0.2.127 is broken for the nightly we use.

Even if we unblock cargo-apk specifically, we'll have to be careful to avoid bumping libc:

rust-gpu/Cargo.lock

Lines 1183 to 1185 in 0866cf5

	[[package]]
	name = "libc"
	version = "0.2.112"

(until we rustup again, that is)

I'll try see what I can do for now, maybe cargo +stable install ... will be enough.

EDIT: alright, that does work:

• Attempt to unbreak CI (Android / libc 0.2.127). #891