Switch CI build timings from --timings to -Zbuild-analysis

mergeconflict · mergeconflict · commit 044b62fb9806 · 2026-03-13T17:52:35.000-04:00
Replace --timings (HTML) with -Zbuild-analysis (JSONL) for per-crate
build timing data. Both cargo invocations use identical flags to avoid
cache invalidation. RUSTC_BOOTSTRAP=1 is required for the unstable
-Zbuild-analysis flag. Output is collected from $CARGO_HOME/log/ and
published as cargo-build-analysis.jsonl.
diff --git a/.github/buildomat/build-and-test.sh b/.github/buildomat/build-and-test.sh
@@ -105,19 +105,25 @@ export TMPDIR="$TEST_TMPDIR"
 export RUST_BACKTRACE=1
 # We're building once, so there's no need to incur the overhead of an incremental build.
 export CARGO_INCREMENTAL=0
+# This allows us to use -Zbuild-analysis to collect per-crate build timing
+# data in JSONL format.
+export RUSTC_BOOTSTRAP=1
+
 # Build all the packages and tests, and keep track of how long each took to build.
 #
 # The build graph ends up building several bin/test targets that depend on
 # omicron-nexus at the same time, which uses significant memory to compile on
 # illumos. To mitigate this we build everything except omicron-nexus's bin/test
 # targets first, then finish the build after.
 #
-# --timings produces an HTML timing report in target/cargo-timings/.
-ptime -m cargo build --timings \
+# Both invocations use the same flags to avoid cache invalidation.
+# We collect timing data only from the second (full workspace) build.
+ptime -m cargo --config 'build.analysis.enabled=true' build -Zbuild-analysis \
     --workspace --exclude=omicron-nexus --tests --locked --verbose
-ptime -m cargo build --timings \
+ptime -m cargo --config 'build.analysis.enabled=true' build -Zbuild-analysis \
     --workspace --tests --locked --verbose
-cp target/cargo-timings/cargo-timing.html "$OUTPUT_DIR/cargo-timing.html"
+cp "$(ls -t "$CARGO_HOME/log/"*.jsonl | head -1)" \
+    "$OUTPUT_DIR/cargo-build-analysis.jsonl"
 
 #
 # We apply our own timeout to ensure that we get a normal failure on timeout
diff --git a/.github/buildomat/jobs/build-and-test-helios.sh b/.github/buildomat/jobs/build-and-test-helios.sh
@@ -29,8 +29,8 @@
 #:
 #: [[publish]]
 #: series = "build-info-helios"
-#: name = "cargo-timing.html"
-#: from_output = "/work/cargo-timing.html"
+#: name = "cargo-build-analysis.jsonl"
+#: from_output = "/work/cargo-build-analysis.jsonl"
 #:
 #: [[publish]]
 #: series = "live-tests"
diff --git a/.github/buildomat/jobs/build-and-test-linux.sh b/.github/buildomat/jobs/build-and-test-linux.sh
@@ -28,8 +28,8 @@
 #:
 #: [[publish]]
 #: series = "build-info-linux"
-#: name = "cargo-timing.html"
-#: from_output = "/work/cargo-timing.html"
+#: name = "cargo-build-analysis.jsonl"
+#: from_output = "/work/cargo-build-analysis.jsonl"
 #:
 #: [[publish]]
 #: series = "nextest-recording-linux"
