ci: run LDC tests again

Now that LDC is in Stretch again, we can finally test with both
compilers again.

.travis.yml

@@ -8,7 +8,7 @@ services:
 
 d:
   - gdc
-  #- ldc -- LDC has problems with parallelization (doesn't seem to work on Package[] array)
+  - ldc
 
 before_script:
   - docker build -t asgen -f test/ci/Dockerfile .

test/ci/Dockerfile

@@ -24,6 +24,7 @@ RUN apt-get install -yq --no-install-recommends \
 
 # install dependencies only for appstream-generator
 RUN apt-get install -yq --no-install-recommends \
+    ldc \
     dub \
     meson \
     libmustache-d-dev \

test/ci/build_and_test.sh

@@ -1,19 +1,19 @@
 #!/bin/sh
-set -e
-
-echo "D compiler: $DC"
-set -x
-dub --version
-
 #
 # This script is supposed to run inside the AppStream Generator Docker container
 # on the CI system.
 #
+set -e
 
-# Build with dub
-dub build --parallel -v
+echo "D compiler: $DC"
+set -v
+$DC --version
+dub --version
+meson --version
 
+#
 # Build with Meson
+#
 mkdir -p build && cd build
 meson ..
 ninja
@@ -25,6 +25,11 @@ ninja
 DESTDIR=/tmp/install-ninja ninja install
 cd ..
 
-# Test getting JS stuff and installing (dub)
+#
+# Build with dub
+#
+dub build --parallel -v --compiler=$DC
+
+# Test getting JS stuff and installing
 make js
 make install DESTDIR=/tmp/install-tmp