gitlab-ci: Install debug packages for valgrind runs

This gives us better backtraces

.gitlab-ci.yml

 variables:
-  DEPS: build-essential git libwlroots-examples wget gnome-session
-        gdb weston valgrind
+  DEPS: build-essential git libwlroots-examples wget gnome-session gdb weston
+  WANT_BUILD_DEPS: "true"
+
+# For the smoke tests we also want debug packages, wlroots/rootston,
+# weston-info, gdb, valgrind, ...
+.smoketest_vars:
+  variables: &smoketest_vars
+    DEPS: libwlroots-examples wget gnome-session gdb weston valgrind
+          libhandy-0.0-0-dbgsym libgtk-3-0-dbgsym libglib2.0-0-dbgsym
+          xvfb
+    WANT_BUILD_DEPS: "false"
 
 before_script:
   - export DEBIAN_FRONTEND=noninteractive
   - apt-get -y update
-  - apt-get -y install wget gnupg eatmydata
+  - apt-get -y install wget ca-certificates gnupg eatmydata
   - echo "deb http://ci.puri.sm/ scratch librem5" > /etc/apt/sources.list.d/ci.list
   - wget -O- https://ci.puri.sm/ci-repo.key | apt-key add -
+  - echo "deb http://debug.mirrors.debian.org/debian-debug/ buster-debug main" > /etc/apt/sources.list.d/debug.list
   - eatmydata apt-get -y update
-  - eatmydata apt-get -y build-dep .
+  - '[ "$WANT_BUILD_DEPS" != "true" ] || eatmydata apt-get -y build-dep .'
   - eatmydata apt-get -y install $DEPS
   - ulimit -c unlimited
 
@@ -39,6 +49,7 @@ test:native:
 test:smoke:one-output:
   <<: *tags
   stage: test
+  variables: *smoketest_vars
   dependencies:
     - build:native
   script:
@@ -54,6 +65,7 @@ test:smoke:one-output:
 test:smoke:two-outputs:
   <<: *tags
   stage: test
+  variables: *smoketest_vars
   dependencies:
     - build:native
   script:
@@ -69,6 +81,7 @@ test:smoke:two-outputs:
 test:smoke:valgrind:
   <<: *tags
   stage: test
+  variables: *smoketest_vars
   dependencies:
     - build:native
   script: