Add source tarballs to our releases

.github/workflows/main.yml

@@ -407,6 +407,10 @@ jobs:
     - uses: actions/checkout@v2
       with:
         submodules: true
+    # On one builder produce the source tarball since there's no need to produce
+    # it everywhere
+    - run: ./ci/build-src-tarball.sh
+      if: matrix.build == 'x86_64-linux'
     - uses: ./.github/actions/install-rust
     - uses: ./.github/actions/binary-compatible-builds
       with:

ci/build-src-tarball.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+set -ex
+
+# Determine the name of the tarball
+tag=dev
+if [[ $GITHUB_REF == refs/tags/v* ]]; then
+  tag=${GITHUB_REF#refs/tags/}
+fi
+pkgname=wasmtime-$tag-src
+
+# Vendor all crates.io dependencies since this is supposed to be an
+# offline-only-compatible tarball
+mkdir .cargo
+cargo vendor > .cargo/config.toml
+
+# Create the tarball from the destination
+tar -czf /tmp/$pkgname.tar.gz --transform "s/^\./$pkgname/S" --exclude=.git .
+mkdir -p dist
+mv /tmp/$pkgname.tar.gz dist/