Statically compile the binaries when releasing; it's maybe easier. (#441

)

This is also an attempt to help fix the `entropy-js` test failures in
CI. We are able to get tests to pass locally (on both macOS and Linux
hosts), but for some reason the binaries behave differently in CircleCI.
Maybe we are missing some environmental difference between the various
places we're running builds; if we statically compile the binaries, they
might have fewer things that can go wrong when moving across machines.

.github/workflows/build-and-release.yaml

@@ -17,7 +17,7 @@ jobs:
     name: Build and upload binaries
     runs-on: ubuntu-22.04
     container:
-      image: rust:1.68.2-slim-bullseye
+      image: rust:1.73.0-slim-bullseye
     outputs:
       git_ref_basename: ${{ steps.git-ref-basename.outputs.git_ref_basename }}
     steps:
@@ -72,33 +72,26 @@ jobs:
           key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
       - name: Build binaries.
         env:
+          GIT_SSH_COMMAND: ssh -F ~/.ssh/config
+          RUSTFLAGS: -C target-feature=+crt-static -C strip=symbols
           # We set this environment variables because Cargo does not
           # itself actually support using OpenSSH config files. See:
           # https://doc.rust-lang.org/cargo/appendix/git-authentication.html#ssh-authentication
           CARGO_NET_GIT_FETCH_WITH_CLI: true
-          GIT_SSH_COMMAND: ssh -F ~/.ssh/config
-        run: |
-          cargo build --release
-      # TODO: Why doesn't `cargo build --release` strip debug info and
-      #       symbols from the built binary by default? Let's do that.
-      - name: Strip built binaries.
-        shell: bash
-        env:
-          DEBIAN_FRONTEND: noninteractive
         run: |
-          echo "Before stripping:"
-          ls -l target/release/{entropy,server} # Show unstripped size.
-          strip target/release/{entropy,server} # Actually strip.
-          echo "After stripping:"
-          ls -l target/release/{entropy,server} # Show stripped size.
+          # Pass `--target` explicitly because of
+          # https://github.com/rust-lang/rust/issues/78210
+          cargo build --release --target x86_64-unknown-linux-gnu
       - uses: actions/upload-artifact@v3
         with:
           name: entropy_${{ steps.git-ref-basename.outputs.git_ref_basename }}_${{ runner.os }}_${{ runner.arch }}
-          path: target/release/entropy
+          path: target/x86_64-unknown-linux-gnu/release/entropy
+          if-no-files-found: error
       - uses: actions/upload-artifact@v3
         with:
           name: server_${{ steps.git-ref-basename.outputs.git_ref_basename }}_${{ runner.os }}_${{ runner.arch }}
-          path: target/release/server
+          path: target/x86_64-unknown-linux-gnu/release/server
+          if-no-files-found: error
 
   # Creates a new GitHub Release, adding built artifacts as release assets.
   release: