omicron-package: work around cargo issue 8157

[iliana]

#5799 modified the cargo build command line omicron-package runs. Previously it built up a list of packages to be built using the -p flag; that PR changed it to use --bin. The goal was to build only the binaries that are necessary for shipping; this avoids building sled-agent-sim during releng, for instance.

We did not realize it at the time, but this invited the specter of rust-lang/cargo#8157 to wreak havoc; namely:

• Without --package, Cargo uses the default-members key of the workspace Cargo.toml to determine which packages to build. --bin does not cause the same thing to happen; saying --bin does not imply --package [the package that the bin belongs to].
• omicron-dev belongs to default-members and has a normal dependency on nexus-test-utils, which enables the "testing" feature of nexus-db-queries.

#7208 is a known result of this problem, but there might be more.

Fortunately the solution seems fairly easy, without reverting the relevant changes from #5799: use both --package and --bin. With this change, the "testing" feature is no longer shown in the cargo build --unit-graph and nm target/release/nexus | demangle | grep validate_volume_invar no longer shows any matching testing-only symbols.

For posterity, the full command omicron-package runs is now (from the log): "cargo" "build" "--package" "dns-server" "--package" "internal-dns-cli" "--package" "omicron-clickhouse-admin" "--package" "omicron-cockroach-admin" "--package" "omicron-gateway" "--package" "omicron-nexus" "--package" "omicron-omdb" "--package" "omicron-sled-agent" "--package" "oximeter-collector" "--package" "oxlog" "--package" "sp-sim" "--package" "wicket" "--package" "wicketd" "--package" "zone-setup" "--bin" "clickhouse-admin-keeper" "--bin" "clickhouse-admin-server" "--bin" "clickhouse-admin-single" "--bin" "clickhouse-schema-updater" "--bin" "cockroach-admin" "--bin" "dns-server" "--bin" "dnsadm" "--bin" "dnswait" "--bin" "mgs" "--bin" "nexus" "--bin" "omdb" "--bin" "oximeter" "--bin" "oxlog" "--bin" "schema-updater" "--bin" "sled-agent" "--bin" "sp-sim" "--bin" "wicket" "--bin" "wicketd" "--bin" "zone-bundle" "--bin" "zone-setup" "--features" "switch-asic" "--release"

[sunshowers]

thanks for jumping so quickly on this!

[sunshowers]

Could you add a comment here about why this is necessary? Just a link to the issue or this PR would do.

Also worth noting somewhere (if not already done) that when source.rust is defined, the table key (e.g. the omicron-nexus in [package.omicron-nexus]) is the name of the corresponding Rust crate.

[jmpesp]

It may also be useful to link to rust-lang/cargo#8157 ?

[davepacheco]

Also worth noting somewhere (if not already done) that when source.rust is defined, the table key (e.g. the omicron-nexus in [package.omicron-nexus]) is the name of the corresponding Rust crate.

This is mentioned here:

omicron/package-manifest.toml

Lines 16 to 17 in d01b2ee

	# If the package involves building a Rust package in the same workspace,
	# then the Rust package *must* have the same name as the Omicron package.

but I agree it's non-obvious and it wouldn't hurt to mention it in other places where a reader might not know.

[jmpesp]

To be clear, in the comment here. I know the PR has it!

[iliana]

acbe39a does most of this; I think the particular detail about how to write package-manifest.toml is documented in the file itself:

omicron/package-manifest.toml

Lines 12 to 17 in d01b2ee

	# (1) "local": packages whose contents come from any combination of files in the
	# current directory, blobs stored in S3, or the result of building a Rust
	# package in the current workspace
	#
	# If the package involves building a Rust package in the same workspace,
	# then the Rust package *must* have the same name as the Omicron package.

But I think I improved the comments to make it clearer in that code's context.