Add a test for the substitution of CA derivations

tests/content-addressed-remote-cache.sh

@@ -4,11 +4,23 @@ source common.sh
 
 clearStore
 clearCache
+clearCache
+
+export REMOTE_STORE=file://$cacheDir
 
-commonFlags=(--experimental-features 'ca-derivations ca-references nix-command')
+commonFlags=( \
+    ./content-addressed.nix -A transitivelyDependentCA \
+    --arg seed 1 \
+    --experimental-features 'ca-derivations ca-references nix-command' \
+    --no-out-link \
+)
 
-drvPath=$(nix-instantiate "${commonFlags[@]}" ./content-addressed.nix -A transitivelyDependentCA --arg seed 1)
-nix copy "${commonFlags[@]}" --to file://$cacheDir $drvPath\!out
+nix-build "${commonFlags[@]}" --post-build-hook $PWD/push-to-store.sh
 
 clearStore
-nix copy "${commonFlags[@]}" --from file://$cacheDir $drvPath\!out --no-require-sigs
+# XXX: The `grep` call is a work around the fact that `-j0` currently doesn't
+# take the possibility that drvs might be resolved into account, so would fail
+# because Nix can't know *a priori* that everything is already in the binary
+# cache
+nix-build "${commonFlags[@]}" --no-require-sigs --substituters file://$cacheDir |& \
+    (! grep -q 'Building a')

tests/local.mk

@@ -35,6 +35,7 @@ nix_tests = \
   recursive.sh \
   describe-stores.sh \
   flakes.sh \
+  content-addressed-remote-cache.sh \
   content-addressed.sh
   # parallel.sh
   # build-remote-content-addressed-fixed.sh \

tests/push-to-store.sh

@@ -2,4 +2,4 @@
 set -x
 
 echo Pushing "$OUTPUTS" to "$REMOTE_STORE"
-printf "%s" "$OUTPUTS" | xargs -d: nix copy --to "$REMOTE_STORE" --no-require-sigs
+printf "%s" "$OUTPUTS" | xargs nix copy --experimental-features 'ca-derivations ca-references nix-command' --to "$REMOTE_STORE" --no-require-sigs