CI: harden verify task (install file, non-fatal diagnostics)

ober

8611b28fcd6225fc17770341aadba78d870502e2

diff --git a/.build.yml b/.build.yml
index 24de8a5..18499b1 100644
--- a/.build.yml
+++ b/.build.yml
@@ -6,6 +6,7 @@ packages:
   - qt6-base-dev
   - qt6-webengine-dev
   - libgl1-mesa-dev
+  - file
 sources:
   - https://git.sr.ht/~lisp/jerboa-browser
 artifacts:
@@ -20,9 +21,11 @@ tasks:
   - verify: |
       cd jerboa-browser
       so=qt-webengine/build/libjerboa_browser.so
-      test -f "$so" || { echo "missing $so"; exit 1; }
-      file "$so"
+      tb=qt-webengine/build/jerboa-browser-0.0.1-linux-x86_64.tar.gz
+      test -f "$so" || { echo "MISSING $so"; exit 1; }
+      test -f "$tb" || { echo "MISSING $tb"; exit 1; }
+      file "$so" || true
       echo "--- Qt links ---"
-      ldd "$so" | grep -i 'Qt6\|webengine' || true
+      ldd "$so" | grep -i 'qt6\|webengine' || true
       echo "--- tarball ---"
-      ls -lh qt-webengine/build/jerboa-browser-0.0.1-linux-x86_64.tar.gz
+      ls -lh "$tb"