Coverage index page of "Build" shows 0 coverage if compare view

[exoego]

If compare view (--branch BRANCH or --mode-CI BRANCH is used), a coverage index page shows the names of changed files, with 0% coverage.

If I switch to the `main` or `rubycritic-setup` branch from the above menu, their coverage index pages shows non-zero coverages.

"Build" compare/simple_cov_index.html	target branch compare/main/simple_cov_index.html	source branch compare/rubycritic-setup/simple_cov_index.html

I expect the "Build" coverage index page shows the coverages of the changed files.