[githooks][pre-push] Run steps in parallel

While we're here, add `-q` flags to all `cargo` invocations in scripts
in the `ci` directory.

On my 2020 M1 MacBook Air, this reduces the time to execute
`./githooks/pre-push` from 3.9s to 1.4s.

ci/check_all_toolchains_tested.sh

@@ -11,6 +11,6 @@ set -eo pipefail
 diff \
  <(cat .github/workflows/ci.yml | yq '.jobs.build_test.strategy.matrix.toolchain | .[]' | \
  sort -u | grep -v '^\(msrv\|stable\|nightly\)$') \
- <(cargo metadata --format-version 1 | \
+ <(cargo metadata -q --format-version 1 | \
  jq -r ".packages[] | select(.name == \"zerocopy\").metadata.\"build-rs\" | keys | .[]" | \
  sort -u)

ci/check_msrv.sh

@@ -3,7 +3,7 @@ set -eo pipefail
 
 # Usage: msrv <crate-name>
 function msrv {
- cargo metadata --format-version 1 | jq -r ".packages[] | select(.name == \"$1\").rust_version"
+ cargo metadata -q --format-version 1 | jq -r ".packages[] | select(.name == \"$1\").rust_version"
 }
 
 ver_zerocopy=$(msrv zerocopy)

ci/check_readme.sh

@@ -4,7 +4,7 @@ set -eo pipefail
 # Install again in case the installation failed during the
 # `generate_cache` step. We treat that step as best-effort and
 # suppress all errors from it.
-cargo install cargo-readme --version 3.2.0 -q
+cargo install -q cargo-readme --version 3.2.0
 
 diff <(cargo -q run --manifest-path tools/Cargo.toml -p generate-readme) README.md
 exit $?

ci/check_versions.sh

@@ -3,7 +3,7 @@ set -eo pipefail
 
 # Usage: version <crate-name>
 function version {
- cargo metadata --format-version 1 | jq -r ".packages[] | select(.name == \"$1\").version"
+ cargo metadata -q --format-version 1 | jq -r ".packages[] | select(.name == \"$1\").version"
 }
 
 ver_zerocopy=$(version zerocopy)
@@ -13,7 +13,7 @@ ver_zerocopy_derive=$(version zerocopy-derive)
 function dependency-version {
  KIND="$1"
  TARGET="$2"
- cargo metadata --format-version 1 \
+ cargo metadata -q --format-version 1 \
  | jq -r ".packages[] | select(.name == \"zerocopy\").dependencies[] | select((.name == \"zerocopy-derive\") and .kind == $KIND and .target == $TARGET).req"
 }
 

githooks/pre-push

@@ -1,10 +1,14 @@
 #!/usr/bin/env bash
 set -eo pipefail
 echo "Running pre-push git hook: $0"
-# forego redirecting stdout to /dev/null on check_fmt.sh because the output
-# from cargofmt is useful (and the good stuff is not delivered by stderr)
-./ci/check_fmt.sh
-./ci/check_job_dependencies.sh > /dev/null
-./ci/check_msrv.sh > /dev/null
-./ci/check_readme.sh > /dev/null
-./ci/check_versions.sh > /dev/null
+# Forego redirecting stdout to /dev/null on check_fmt.sh because the output from
+# `cargo fmt` is useful (and the good stuff is not delivered by stderr).
+#
+# Background all jobs and wait for them so they can run in parallel.
+./ci/check_fmt.sh &
+./ci/check_job_dependencies.sh >/dev/null &
+./ci/check_msrv.sh >/dev/null &
+./ci/check_readme.sh >/dev/null &
+./ci/check_versions.sh >/dev/null &
+
+wait