Add min test for cross build

Author: oech3

.github/workflows/CICD.yml

@@ -269,6 +269,9 @@ jobs:
       with:
         persist-credentials: false
     - uses: dtolnay/rust-toolchain@stable
+    - uses: dtolnay/rust-toolchain@stable
+        with:
+          target: aarch64-unknown-linux-gnu
     - uses: taiki-e/install-action@nextest
     - uses: Swatinem/rust-cache@v2
     - name: Install/setup prerequisites
@@ -287,7 +290,10 @@ jobs:
         if [[ -d target ]]; then
           mv -T target target.cache
         fi
-        # Actually do the build
+        # Minimal cross-built with native uudoc
+        make UTILS=true RUSTC_ARCH="--target aarch64-unknown-linux-gnu"
+        ./target/debug/uudoc manpage
+        # build (host)
         make build
         echo "Check that target directory will be ignored by backup tools"
         test -f target/CACHEDIR.TAG

GNUmakefile

@@ -27,7 +27,7 @@ RM := rm -rf
 # Binaries
 CARGO  ?= cargo
 CARGOFLAGS ?=
-RUSTC_ARCH ?= # should be empty instead of --target $(shell rustc -vV | sed -n 's/host: //p') to share crates ar target dir
+RUSTC_ARCH ?= # should be empty except for cross-build, not --target $(shell rustc -vV | sed -n 's/host: //p')
 
 # Install directories
 PREFIX ?= /usr/local