In vast majority of git projects, master means branch with latest developments, but in Nim, master points to latest dot release IIUC, and devel is the branch with latest developments.
Here's an example where this non-standard convention gets in the way:
when deleting a feature branch after it was merged (via a PR) to devel, git complains (with a warning) because it expects HEAD to point to master, not a custom name like devel:
git checkout devel
git pull --ff-only
git branch -d pr_fix_7492_doAssert_bad_stacktrace_simple
warning: deleting branch 'pr_fix_7492_doAssert_bad_stacktrace_simple' that has been merged to
'refs/remotes/rdev/pr_fix_7492_doAssert_bad_stacktrace_simple', but not yet merged to HEAD.
Deleted branch pr_fix_7492_doAssert_bad_stacktrace_simple (was 11e70d109).
if we were using master instead of devel, we wouldn't have this warning (IIUC)