Fixes?

internal/gitea/gitea.go

@@ -8,6 +8,17 @@ import (
 	giteaSDK "code.gitea.io/sdk/gitea"
 )
 
+// isPRsDisabledError returns true when the Gitea server rejects a PR operation
+// because the Pull Requests unit is disabled on the repository.
+func isPRsDisabledError(err error) bool {
+	if err == nil {
+		return false
+	}
+	msg := err.Error()
+	return strings.Contains(msg, "Can't read pulls") ||
+		strings.Contains(msg, "UnitTypeCode")
+}
+
 const prMarker = "<!-- stamp-release-pr -->"
 
 // Client wraps the Gitea API.
@@ -19,12 +30,18 @@ type Client struct {
 
 const commentMarker = "<!-- stamp-pr-comment -->"
 
-// NewClient creates a Gitea client from GITEA_TOKEN and GITEA_BASE_URL environment variables.
+// NewClient creates a Gitea client from GITEA_BASE_URL and a token environment variable.
+// The token is read from STAMP_GITEA_TOKEN first, falling back to GITEA_TOKEN.
+// STAMP_GITEA_TOKEN should be used in CI to avoid the reserved GITEA_TOKEN name that
+// Gitea Actions injects automatically (with limited scopes).
 // The repoSlug must be in "owner/repo" format.
 func NewClient(repoSlug string) (*Client, error) {
-	token := os.Getenv("GITEA_TOKEN")
+	token := os.Getenv("STAMP_GITEA_TOKEN")
 	if token == "" {
-		return nil, fmt.Errorf("GITEA_TOKEN environment variable is not set")
+		token = os.Getenv("GITEA_TOKEN")
+	}
+	if token == "" {
+		return nil, fmt.Errorf("neither STAMP_GITEA_TOKEN nor GITEA_TOKEN environment variable is set")
 	}
 	baseURL := os.Getenv("GITEA_BASE_URL")
 	if baseURL == "" {
@@ -87,6 +104,12 @@ func (c *Client) UpsertPR(head, base, title, body string) (int64, string, error)
 		State: giteaSDK.StateOpen,
 	})
 	if err != nil {
+		if isPRsDisabledError(err) {
+			return 0, "", fmt.Errorf(
+				"pull requests are disabled on %s/%s — enable them under Settings → General → Features → Pull Requests",
+				c.owner, c.repo,
+			)
+		}
 		return 0, "", fmt.Errorf("listing pull requests: %w", err)
 	}
 
@@ -116,6 +139,12 @@ func (c *Client) UpsertPR(head, base, title, body string) (int64, string, error)
 		Body:  markedBody,
 	})
 	if err != nil {
+		if isPRsDisabledError(err) {
+			return 0, "", fmt.Errorf(
+				"pull requests are disabled on %s/%s — enable them under Settings → General → Features → Pull Requests",
+				c.owner, c.repo,
+			)
+		}
 		return 0, "", fmt.Errorf("creating pull request: %w", err)
 	}
 	return pr.Index, pr.HTMLURL, nil