Add musl build target for CI.

.azure/install-rust.yml

@@ -43,6 +43,7 @@ steps:
       set -ex
       rustup update --no-self-update $RUST_TOOLCHAIN
       rustup default $RUST_TOOLCHAIN
+      rustup target add x86_64-unknown-linux-musl
 
       rustc -Vv
       cargo -V

Makefile

@@ -258,6 +258,12 @@ check: check-bench
 release:
 	cargo build --release --features backend-singlepass,backend-cranelift,backend-llvm,loader-kernel,experimental-io-devices,log/release_max_level_off
 
+# Release with musl target
+release-musl:
+	# backend-llvm is not included due to dependency on wabt.
+	# experimental-io-devices is not included due to missing x11-fb.
+	cargo build --release --target x86_64-unknown-linux-musl --features backend-singlepass,backend-cranelift,loader-kernel,log/release_max_level_off,wasi --no-default-features
+
 # Only one backend (cranelift)
 release-clif:
 	# If you are on macOS, you will need mingw-w64 for cross compiling to Windows

azure-pipelines.yml

@@ -141,6 +141,9 @@ jobs:
       - bash: make release
         displayName: Build (*nix)
         condition: and(succeeded(), not(eq(variables['Agent.OS'], 'Windows_NT')))
+      - bash: make release-musl
+        displayName: Build (Linux, x86_64-unknown-linux-musl)
+        condition: and(succeeded(), eq(variables['Agent.OS'], 'Linux'))
       - bash: make release-llvm
         displayName: Build (Windows)
         condition: and(succeeded(), eq(variables['Agent.OS'], 'Windows_NT'))