ci: add a basic illumos test job

This commit adds a simple test job for illumos using Buildomat. I'd like
to make some more improvements and add docs before merging this, but I
want to see if it even works first.

.github/buildomat/jobs/test-full.sh

@@ -0,0 +1,44 @@
+#!/bin/bash
+#:
+#: name = "illumos-test-full"
+#: variety = "basic"
+#: target = "omnios-r151038"
+#: rust_toolchain = "stable"
+
+# basic illumos test job with --features full.
+# TODO(eliza): consider splitting the "build" and "test" jobs into separate
+# buildomat jobs, so that the build and test jobs can fail independently.
+
+set -o errexit
+set -o pipefail
+set -o xtrace
+
+
+# These are the same env vars that are set for all GitHub Actions CI jobs.
+export RUSTFLAGS="-Dwarnings"
+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
+
+# NOTE: Currently we use the latest cargo-nextest release, since this is what
+# the Linux CI jobs do. If we ever start pinning our nextest version, this
+# should be changed to match that.
+NEXTEST_VERSION='latest'
+
+
+curl -sSfL --retry 10 "https://get.nexte.st/$NEXTEST_VERSION/illumos" | gunzip | tar -xvf - -C ~/.cargo/bin
+
+# Print the current test execution environment
+uname -a
+cargo --version
+rustc --version
+
+banner build
+ptime -m cargo test --no-run --all --verbose --features full
+
+banner tests
+ptime -m cargo nextest run --features full
+
+banner doctests
+ptime -m cargo test --doc --verbose --features full