macOS to Android cross compile error: No such file or directory

[EternalDeiwos]

I've tried a bunch of things to get aarch64 and armaebi-v7a to build for android

• Tried building on both macOS and linux (x86_64).
• Changing the API version in build.rs
• Regenerating my standalone android NDK toolchain (with --api 21)
• Specifying the correct gcc compiler (from the NDK toolchain) in `.cargo/config
• Multiple versions of ring -- specifically 0.12.1 and 0.13.0.

I've also made sure that I am able to build a simple static library for these architectures when not requiring/using ring.

The build fails to compile multiple files of .c/.S crypto code with the error:

$ cargo build --target aarch64-linux-android --release
...
No such file or directory (os error 2)', ring/build.rs:633:8
(what file is this referring to?)

I started at #486 but the build still fails even for the exact rev that shows passing tests on travis. If I had to guess, I'd say the problem is related to cross-compiling the C/ASM code specifically.

[EternalDeiwos]

Update
In addition to the above; I was able to successfully build v0.12.1 for aarch64 using the following environment variables:

PATH=$(PATH):$(NDK_STANDALONE)/arm64/bin \
CC=aarch64-linux-android-gcc \
CXX=aarch64-linux-android-g++ \
cargo build --target aarch64-linux-android --release --lib

The same worked for the armaebi, armaebi-v7a, i686 and x86_64 android builds which will allow me to use the static libraries in JNI. Aside from the API differences mentioned in #486, I don't think there's an issue (maybe aside from some documentation on the topic in BUILDING.md). The above error which I created the issue on was clearly a configuration problem on my end.

[EternalDeiwos]

Update

Our exact setup can be seen here.

[briansmith]

I'm closing this as a combination of "dupe of #486" and "no longer an issue."

Thanks for all the help here.