[atti92]

The Linux desktop job spent 10m16s installing native dependencies, including 9m56s downloading 71.9 MB from the runner's HTTP Azure mirror at 121 kB/s. Building the app itself took 62 seconds.

Install dependencies from the official Ubuntu HTTPS archives, omit optional recommended packages, and cache downloaded .deb files with actions/cache. Refresh package indexes and perform normal APT dependency resolution on every run, including cache hits. Rotate the cache weekly and invalidate it when the dependency script changes. Binary build triggers remain tags and manual requests only.

Measured validation on GitHub-hosted Ubuntu 24.04:

• Baseline: dependency install 10m16s; entire Linux job 12m17s.
• Empty package cache: dependency install 1m44s; entire Linux job 3m33s. Successful build: https://github.com/openutm/utm-adapter/actions/runs/39801878385
• Restored package cache: dependency install 34s, with 0 bytes of package downloads. Linux artifact uploaded about 2m41s after job start: https://github.com/openutm/utm-adapter/actions/runs/39802478343
• Linux and Windows PR tests and frontend checks passed. Local bash syntax check, actionlint for both workflows, and git diff --check passed.