From 084a6d2d4380abd3894058fff5829e4a7e2e5c5e Mon Sep 17 00:00:00 2001
From: "sentry[bot]" <39604003+sentry[bot]@users.noreply.github.com>
Date: Sun, 20 Sep 2026 22:44:42 +0000
Subject: [PATCH] fix(grep): Handle ripgrep literal newline regex error

---
 packages/junior/src/chat/tools/sandbox/grep.ts |  2 +-
 .../unit/tools/sandbox/file-tools.test.ts      | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/packages/junior/src/chat/tools/sandbox/grep.ts b/packages/junior/src/chat/tools/sandbox/grep.ts
index 1f32223249..0773708c94 100644
--- a/packages/junior/src/chat/tools/sandbox/grep.ts
+++ b/packages/junior/src/chat/tools/sandbox/grep.ts
@@ -334,7 +334,7 @@ async function grepFilesWithRipgrep(params: {
         cause: new Error(detail),
       });
     }
-    if (/regex parse error|error parsing regex/i.test(detail)) {
+    if (/regex parse error|error parsing regex|is not allowed in a regex/i.test(detail)) {
       throw new ToolInputError(`Invalid regex pattern: ${params.pattern}`, {
         cause: new Error(detail),
       });
diff --git a/packages/junior/tests/unit/tools/sandbox/file-tools.test.ts b/packages/junior/tests/unit/tools/sandbox/file-tools.test.ts
index cf65c1f4e5..988662413e 100644
--- a/packages/junior/tests/unit/tools/sandbox/file-tools.test.ts
+++ b/packages/junior/tests/unit/tools/sandbox/file-tools.test.ts
@@ -416,6 +416,24 @@ describe("sandbox file tools", () => {
       message: "Invalid glob: {foo,{bar,baz}}",
     });
 
+    const literalNewline: SandboxCommandRunner = async () => ({
+      exitCode: 2,
+      stderr: 'rg: the literal "\\n" is not allowed in a regex',
+      stdout: "",
+    });
+
+    await expect(
+      grepFiles({
+        fs: memory.fs,
+        path: "src",
+        pattern: "foo\nbar",
+        runCommand: literalNewline,
+      }),
+    ).rejects.toMatchObject({
+      name: "ToolInputError",
+      message: "Invalid regex pattern: foo\nbar",
+    });
+
     const lifecycleFailure = new Error("sandbox_stopped");
     await expect(
       findFiles({