tailscale - build upstreams go fork and use that

metadata/com.tailscale.ipn.yml

@@ -1169,13 +1169,27 @@ Builds:
     sudo:
       - apt-get update
       - apt-get install -y -t bullseye-backports golang-go
-      - apt-get install -y make
+      - apt-get install -y build-essential
     gradle:
       - fdroid
+    srclibs:
+      - tailscale-go@e6ce5b50036022c91783161890eabecfddc5ae79
     prebuild:
       - sdkmanager 'platforms;android-31' 'build-tools;31.0.0'
-      - sed -i -e 's!$(TOOLCHAINDIR)/go/bin/!!' ../Makefile
-    build: ANDROID_NDK_ROOT=$$NDK$$ make -C .. release_aar
+      - sed -i -e '/rm -rf/,+2d' ../Makefile
+    build:
+      - export TOOLCHAINREV=$(go run tailscale.com/cmd/printdep --go)
+      - export TOOLCHAINDIR=${HOME}/.cache/tailscale-android-go-$TOOLCHAINREV
+      - pushd $$tailscale-go$$
+      - git checkout $TOOLCHAINREV
+      - pushd src
+      - ./make.bash
+      - popd
+      - popd
+      - mkdir -p $TOOLCHAINDIR
+      - ln -s $$tailscale-go$$ $TOOLCHAINDIR/go
+      - export PATH=$TOOLCHAINDIR/go/bin:$PATH
+      - ANDROID_NDK_ROOT=$$NDK$$ make -C .. release_aar
     ndk: r23b
 
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