diff --git a/.github/workflows/docker.yml b/.github/workflows/docker.yml
index 84b412c..2c11fdb 100644
--- a/.github/workflows/docker.yml
+++ b/.github/workflows/docker.yml
@@ -1,8 +1,6 @@
 name: ci
 on:
   push:
-    tags:
-      - "v*"
 jobs:
   main:
     runs-on: ubuntu-latest
@@ -17,7 +15,8 @@ jobs:
           tags: |
             type=semver,pattern={{version}}
       - uses: docker/setup-buildx-action@v3
-      - uses: docker/login-action@v3
+      - if: ${{ startsWith(github.ref, 'refs/tags/v') }}
+        uses: docker/login-action@v3
         with:
           registry: ghcr.io
           username: ${{ github.actor }}
@@ -25,5 +24,5 @@ jobs:
       - uses: docker/build-push-action@v5
         with:
           context: "{{defaultContext}}:src"
-          push: true
+          push: ${{ startsWith(github.ref, 'refs/tags/v') }}
           tags: ${{ steps.dockermeta.outputs.tags }}
diff --git a/src/explicitcast/explicitcast.go b/src/explicitcast/explicitcast.go
index a4c9476..64824f2 100644
--- a/src/explicitcast/explicitcast.go
+++ b/src/explicitcast/explicitcast.go
@@ -142,7 +142,7 @@ func New() *analysis.Analyzer {
 						if inFunc == nil {
 							t := strings.Builder{}
 							for i, c := range crumbs {
-								t.WriteString(fmt.Sprintf("crumb %d %T %s\n", i, c, p.Fset.Position(c.Pos())))
+								fmt.Fprintf(&t, "crumb %d %T %s\n", i, c, p.Fset.Position(c.Pos()))
 							}
 							panic("ASSERTION!" + p.String() + "\n" + t.String())
 						}