Code coverage report not working

[alamb]

Code coverage was enabled in this PR from @buraksenn

• ci: reintroduce code coverage reporting with cargo-llvm-cov #23336

However, @Jefffrey noticed a problem that makes the report unusable (it doesn't have a base commit to compare with).

If we can't get a code coverage report that shows the coverage change of a PR, I don't think the coverage tests are very useful

when i open https://app.codecov.io/gh/apache/datafusion it seems to show master as default

• the latest commit shown there seems to be pretty old a9f7cac

i cant seem to find main in the dropdown

is this an issue we need to fix? i see a comment on my PR how base (main) doesnt have a coverage report uploaded, is this related?

• Various ScalarValue numeric method fixes & refactors (especially decimal) #23631 (comment)

edit: or maybe its still processing on codecov's end

Originally posted by @Jefffrey in #23336 (comment)

[alamb]

#23336 (comment) from @Jefffrey (error about token required)

oh im seeing this log on main:

info - 2026-07-16 10:36:05,200 -- Found 1 coverage files to report
info - 2026-07-16 10:36:05,200 -- > /__w/datafusion/datafusion/target/codecov.json
info - 2026-07-16 10:36:05,651 -- Upload queued for processing complete
error - 2026-07-16 10:36:05,651 -- Upload queued for processing failed: {"message":"Token required because branch is protected"}

• https://github.com/apache/datafusion/actions/runs/29490778583/job/87596785411

[buraksenn]

It was using CODECOV_TOKEN from repository secrets and since I saw it was working in my branch I did not ping any maintainer about this.

      - name: Upload coverage to codecov.io
        uses: codecov/codecov-action@0fb7174895f61a3b6b78fc075e0cd60383518dac  # v5
        with:
          files: target/codecov.json
          fail_ci_if_error: false
          token: ${{ secrets.CODECOV_TOKEN }}

I think this needs to be checked but I'll take a look in detail

[buraksenn]

Then an admin needs to change default branch to main in codecov: https://community.codecov.com/t/codecov-default-branch-doesn-t-match-gh-default-branch/4442/2

[alamb]

Ok, I added the CODECOV_TOKEN from the codecov UI to https://github.com/apache/datafusion/settings/secrets/actions

Let's see if that fixes the problem