build: Speed up RPM builds by avoiding redundant cargo rebuilds

Cargo.toml

@@ -7,8 +7,6 @@ opt-level = 1 # No optimizations are too slow for us.
 
 [profile.release]
 lto = "thin"
-# We use FFI so this is safest
-panic = "abort"
 # We assume we're being delivered via e.g. RPM which supports split debuginfo
 debug = true
 
@@ -76,7 +74,7 @@ similar-asserts = "2.0.0"
 static_assertions = "1.1.0"
 tempfile = "3.10.1"
 thiserror = "2.0.11"
-tokio = ">= 1.37.0"
+tokio = { version = ">= 1.37.0", features = ["test-util"] }
 tokio-util = { features = ["io-util"], version = "0.7.10" }
 toml = "1.0.0"
 tracing = "0.1.40"

Makefile

@@ -56,6 +56,22 @@ CARGO_OPTIONS ?= --features "$(CARGO_FEATURES)"
 # image configuration rather than documentation.
 DISABLE_DOCS ?=
 
+# Set to 1 to install already-built binaries and man pages without invoking
+# cargo, e.g. from an RPM %install after the binaries were built in %build:
+#   make install SKIP_BUILD=1
+SKIP_BUILD ?=
+
+# Cargo profile used to build xtask (e.g. for man pages). RPM builds set this
+# to `rpm` so xtask shares the %cargo_build profile instead of clobbering its
+# state through the target/release -> target/rpm symlink from %cargo_prep.
+XTASK_PROFILE ?= release
+
+# The cargo command used by the build targets. RPM builds set this to
+# %{__cargo} so the environment (e.g. RUSTC_BOOTSTRAP) matches the
+# %cargo_* macros; otherwise build scripts that depend on it re-run and
+# invalidate the shared build state.
+CARGO ?= cargo
+
 # Build all binaries
 .PHONY: bin
 # The man pages are built first so that the production binary below
@@ -64,16 +80,25 @@ ifneq ($(DISABLE_DOCS),1)
 bin: manpages
 endif
 bin:
-	cargo build --release $(CARGO_OPTIONS) --bins
+	$(CARGO) build --release $(CARGO_OPTIONS) --bins
 
 # The docgen feature this adds implies install-to-disk, so the man pages
 # document the full CLI regardless of CARGO_OPTIONS.
 .PHONY: manpages
 manpages:
-	cargo run --release --package xtask -- manpages -- $(CARGO_OPTIONS)
+	$(CARGO) run --profile $(XTASK_PROFILE) --package xtask -- manpages -- $(CARGO_OPTIONS)
+
+# Convert the man page markdown in docs/src/man without building bootc to
+# sync its generated CLI sections; CI ensures those are already up to date.
+.PHONY: manpages-no-sync
+manpages-no-sync:
+	$(CARGO) run --profile $(XTASK_PROFILE) --package xtask -- manpages --no-sync
 
 .PHONY: completion
+ifneq ($(SKIP_BUILD),1)
 completion: bin
+endif
+completion:
 	mkdir -p target/completion
 	for shell in bash elvish fish powershell zsh; do \
 		target/release/bootc completion $$shell > target/completion/bootc.$$shell; \

contrib/packaging/bootc.spec

@@ -137,8 +137,6 @@ cd %{name}-%{version}-build
 
 %build
 export SYSTEM_REINSTALL_BOOTC_INSTALL_PODMAN_PATH=%{system_reinstall_bootc_install_podman_path}
-# Build this first to avoid feature skew
-make manpages
 
 # Build all binaries
 %if 0%{?container_build}
@@ -156,6 +154,17 @@ cargo build -j%{_smp_build_ncpus} --release %{?with_rhsm:--features rhsm} %{?wit
 %endif
 %endif
 
+# The generated CLI sections in the man page sources are kept in sync by CI,
+# so just convert them; this avoids building bootc a second time.
+# Outside of container builds, use the same cargo environment and profile as
+# %%cargo_build/%%cargo_test, so xtask doesn't invalidate their shared state
+# (target/release is a symlink to target/rpm, created by %%cargo_prep).
+%if 0%{?container_build}
+make manpages-no-sync
+%else
+make manpages-no-sync XTASK_PROFILE=rpm CARGO="%{__cargo}"
+%endif
+
 %if ! 0%{?container_build}
 %cargo_vendor_manifest
 # https://pagure.io/fedora-rust/rust-packaging/issue/33
@@ -165,8 +174,10 @@ sed -i -e '/https:\/\//d' cargo-vendor.txt
 %endif
 
 %install
-# Pass CARGO_FEATURES explicitly to prevent auto-detection rebuild in install environment
-%make_install INSTALL="install -p -c" CARGO_FEATURES="%{?with_rhsm:rhsm} %{?with_rhel9:rhel9}"
+# Everything was built in %%build; SKIP_BUILD=1 keeps make from invoking cargo
+# again (which would also overwrite the %%cargo_build output in target/rpm via
+# the target/release symlink created by %%cargo_prep).
+%make_install INSTALL="install -p -c" SKIP_BUILD=1
 %if %{with ostree_ext}
 make install-ostree-hooks DESTDIR=%{?buildroot}
 %endif

crates/lib/Cargo.toml

@@ -83,7 +83,6 @@ uapi-version = "0.4.0"
 ostree-ext = { path = "../ostree-ext", features = ["bootc", "internal-testing-api"] }
 similar-asserts = { workspace = true }
 static_assertions = { workspace = true }
-tokio = { workspace = true, features = ["test-util"] }
 
 [features]
 default = ["install-to-disk", "selinux"]

crates/xtask/src/man.rs

@@ -835,6 +835,13 @@ pub fn generate_man_pages(sh: &Shell, cargo_options: &[String]) -> Result<()> {
     generate_pages(sh, false)
 }
 
+/// Generate manuals from the Markdown as-is, without building bootc to sync
+/// the generated CLI sections first.
+#[context("Generating manpages")]
+pub fn generate_man_pages_no_sync(sh: &Shell) -> Result<()> {
+    generate_pages(sh, false)
+}
+
 /// Get version from Cargo.toml
 #[context("Querying package version")]
 fn get_package_version() -> Result<String> {

crates/xtask/src/xtask.rs

@@ -79,6 +79,11 @@ struct Cli {
 enum Commands {
     /// Generate man pages
     Manpages {
+        /// Only convert the markdown in docs/src/man, without first building
+        /// bootc to sync its generated CLI sections. CI verifies those are up
+        /// to date, so this is suitable for packaging a release.
+        #[arg(long, conflicts_with = "cargo_options")]
+        no_sync: bool,
         /// Extra options for cargo when building bootc, after `--`
         /// (e.g. `-- --no-default-features --features install-to-disk`)
         #[arg(last = true)]
@@ -395,7 +400,16 @@ fn try_main() -> Result<()> {
     let sh = xshell::Shell::new()?;
 
     match cli.command {
-        Commands::Manpages { cargo_options } => man::generate_man_pages(&sh, &cargo_options),
+        Commands::Manpages {
+            no_sync,
+            cargo_options,
+        } => {
+            if no_sync {
+                man::generate_man_pages_no_sync(&sh)
+            } else {
+                man::generate_man_pages(&sh, &cargo_options)
+            }
+        }
         Commands::GuideManpages => man::generate_guide_man_pages(&sh),
         Commands::CheckDocs => man::check_docs(),
         Commands::UpdateGenerated { command } => match command {