Add a test for the migration of the db between versions

tests/db-migration.sh

@@ -0,0 +1,25 @@
+# Test that we can successfully migrate from an older db schema
+
+# Only run this if we have an older Nix available
+if [[ -z "$OUTER_NIX" ]]; then
+    exit 0
+fi
+
+source common.sh
+
+# Fill the db using the older Nix
+PATH_WITH_NEW_NIX="$PATH"
+export PATH="$OUTER_NIX/bin:$PATH"
+clearStore
+nix-build simple.nix --no-out-link
+nix-store --generate-binary-cache-key cache1.example.org $TEST_ROOT/sk1 $TEST_ROOT/pk1
+dependenciesOutPath=$(nix-build dependencies.nix --no-out-link --secret-key-files "$TEST_ROOT/sk1")
+fixedOutPath=$(IMPURE_VAR1=foo IMPURE_VAR2=bar nix-build fixed.nix -A good.0 --no-out-link)
+
+# Migrate to the new schema and ensure that everything's there
+export PATH="$PATH_WITH_NEW_NIX"
+info=$(nix path-info --json $dependenciesOutPath)
+[[ $info =~ '"ultimate":true' ]]
+[[ $info =~ 'cache1.example.org' ]]
+nix verify -r "$fixedOutPath"
+nix verify -r "$dependenciesOutPath" --sigs-needed 1 --trusted-public-keys $(cat $TEST_ROOT/pk1)

tests/local.mk

@@ -7,6 +7,7 @@ nix_tests = \
   referrers.sh user-envs.sh logging.sh nix-build.sh misc.sh fixed.sh \
   gc-runtime.sh check-refs.sh filter-source.sh \
   local-store.sh remote-store.sh remote-store-old-daemon.sh export.sh export-graph.sh \
+  db-migration.sh \
   timeout.sh secure-drv-outputs.sh nix-channel.sh \
   multiple-outputs.sh import-derivation.sh fetchurl.sh optimise-store.sh \
   binary-cache.sh \