name: Build APK
run-name: ${{ github.event_name == 'pull_request_target' && format('building pr {0} on {1}', github.event.pull_request.number, github.event.pull_request.head.sha) || format('building {0} on {1}', github.ref_name, github.sha) }}
# One job: the two glibc preload libraries the session needs, then the app around them.
# Nothing is built on a developer machine - this workflow is the only thing that produces an apk.
#
# This repo is private, so every minute here is billed. Three caches carry the cost of a rebuild
# down to what actually changed:
# • Gradle's own (dependencies, wrapper, build cache, configuration cache) via setup-gradle
# • the CMake/ninja tree, so a Kotlin-only change does not recompile the compositor
# • the two cross-compiled preloads, which also skips installing the cross toolchain
# A run that changes only Kotlin should not touch the C compiler at all.
on:
push:
branches: [ main ]
# Documentation changes cannot alter the apk, so they do not buy a build.
paths-ignore:
- '**/*.md'
- 'LICENSE'
- '.gitignore'
# A pull request against main builds by itself: the contributor's branch, as it would be once
# merged onto main, comes back as an apk on the run without anyone here pressing a button.
# Every push to the pull request rebuilds it and cancels the build it replaces; a draft waits
# until it is marked ready. pull_request_target rather than pull_request: GitHub does not run
# the latter at all while a pull request conflicts with main, and saying what conflicts is the
# point. The workflow file is always main's; the pull request's own code is checked out below.
pull_request_target:
branches: [ main ]
types: [ opened, synchronize, reopened, ready_for_review ]
paths-ignore:
- '**/*.md'
- 'LICENSE'
- '.gitignore'
workflow_dispatch:
permissions:
contents: read
# The pull-request report below is one comment on the pull request, kept up to date.
pull-requests: write
# A newer push makes the running build pointless; stop paying for it.
concurrency:
group: build-${{ github.event.pull_request.number || github.ref }}
cancel-in-progress: true
env:
# Bump to force the preload cache to miss (e.g. after changing a compiler flag below).
PRELOAD_CACHE_VERSION: v1
jobs:
build:
if: ${{ github.event_name != 'pull_request_target' || !github.event.pull_request.draft }}
runs-on: ubuntu-24.04
timeout-minutes: 45
steps:
# A pull request is checked out at its own head with full history, not at GitHub's merge
# ref: that ref does not exist while the pull request conflicts with main, and the point of
# the next step is to say so and show where.
- uses: actions/checkout@v4
with:
ref: ${{ github.event_name == 'pull_request_target' && github.event.pull_request.head.sha || github.sha }}
# Full history: the merge below needs it (a shallow clone refuses to merge at all).
fetch-depth: 0
# The pull request as it would be once merged onto main is what gets built. When it cannot
# be merged, the conflicting files and the conflicting hunks go into the run summary and the
# pull-request comment, and the job stops here: there is nothing coherent to build.
- name: Merge onto main, or say what conflicts
if: github.event_name == 'pull_request_target'
run: |
set -uo pipefail
git config user.name "ci"
git config user.email "ci@users.noreply.github.com"
git fetch --no-tags origin main
BASE=$(git rev-parse --short origin/main)
HEAD=$(git rev-parse --short HEAD)
if git merge --no-ff --no-edit origin/main >/tmp/merge.out 2>&1; then
{
echo "### Mergeable"
echo
echo "\`$HEAD\` merges cleanly onto main (\`$BASE\`). What follows was built from the merged result."
} > /tmp/pr-merge.md
cat /tmp/pr-merge.md >> "$GITHUB_STEP_SUMMARY"
exit 0
fi
FILES=$(git diff --name-only --diff-filter=U)
if [ -z "$FILES" ]; then
# The merge did not even start (git said why): quote it rather than list nothing.
{
echo "### ERROR: Could not merge onto main (\`$BASE\`)"
echo
echo '```'
cat /tmp/merge.out
echo '```'
} > /tmp/pr-merge.md
cat /tmp/pr-merge.md >> "$GITHUB_STEP_SUMMARY"
echo "::error::git could not merge main: $(head -3 /tmp/merge.out | tr '\n' ' ')"
exit 1
fi
{
echo "### ERROR: Not mergeable - conflicts with main (\`$BASE\`)"
echo
echo "Files that conflict:"
echo
for f in $FILES; do echo "- \`$f\`"; done
echo
echo "Each conflicting hunk, as git leaves it: \`<<<<<<< HEAD\` is this pull request, \`>>>>>>> origin/main\` is main."
echo
for f in $FILES; do
echo "$f
"
echo
echo '```'
awk '/^<<<<<<< /{p=1} p{print} /^>>>>>>> /{p=0}' "$f" | head -300
echo '```'
echo "What went wrong (Gradle)
"
echo
echo '```'
awk '/^\* What went wrong/{p=1} /^\* Try:/{p=0} p{print}' /tmp/build.log 2>/dev/null | head -60
echo '```'
echo "