Correctly pass base branch flag

Fixes cloudflare#559.

cmd/pint/ci.go

@@ -85,10 +85,10 @@ func actionCI(c *cli.Context) error {
 
 	var entries []discovery.Entry
 	if c.Bool(devFlag) {
-		finder := discovery.NewGitBranchFinder(git.RunGit, includeRe, meta.cfg.CI.BaseBranch, meta.cfg.CI.MaxCommits, meta.cfg.Parser.CompileRelaxed())
+		finder := discovery.NewGitBranchFinder(git.RunGit, includeRe, baseBranch, meta.cfg.CI.MaxCommits, meta.cfg.Parser.CompileRelaxed())
 		entries, err = finder.Find()
 	} else {
-		finder := discovery.NewGitBlameFinder(git.RunGit, includeRe, meta.cfg.CI.BaseBranch, meta.cfg.CI.MaxCommits, meta.cfg.Parser.CompileRelaxed())
+		finder := discovery.NewGitBlameFinder(git.RunGit, includeRe, baseBranch, meta.cfg.CI.MaxCommits, meta.cfg.Parser.CompileRelaxed())
 		entries, err = finder.Find()
 	}
 	if err != nil {

cmd/pint/tests/0124_ci_base_branch_flag.txt

@@ -0,0 +1,44 @@
+mkdir testrepo
+cd testrepo
+exec git init --initial-branch=main .
+
+cp ../src/v1.yml rules.yml
+cp ../src/.pint.hcl .
+env GIT_AUTHOR_NAME=pint
+env GIT_AUTHOR_EMAIL=pint@example.com
+env GIT_COMMITTER_NAME=pint
+env GIT_COMMITTER_EMAIL=pint@example.com
+exec git add .
+exec git commit -am 'import rules and config'
+
+exec git checkout -b v2
+cp ../src/v2.yml rules.yml
+exec git commit -am 'v2'
+
+pint.error --no-color ci --base-branch=main
+! stdout .
+cmp stderr ../stderr.txt
+
+-- stderr.txt --
+level=info msg="Loading configuration file" path=.pint.hcl
+level=info msg="Problems found" Fatal=1
+rules.yml:2 Fatal: syntax error: unexpected identifier "bi" (promql/syntax)
+ 2 |   expr: sum(foo) bi(job)
+
+level=fatal msg="Fatal error" error="problems found"
+-- src/v1.yml --
+- record: rule1
+  expr: sum(foo) by(job)
+- record: rule2
+  expr: sum(foo) bi(job)
+
+-- src/v2.yml --
+- record: rule1
+  expr: sum(foo) bi(job)
+- record: rule2
+  expr: sum(foo) bi(job)
+
+-- src/.pint.hcl --
+parser {
+  relaxed = [".*"]
+}

docs/changelog.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## v0.42.1
+
+### Fixed
+
+- Fixed `--initial-branch` flag handling.
+  Value of this flag wasn't being used correctly - #559.
+
 ## v0.42.0
 
 ### Fixed