From 0d11d32f02df1d62139a9f63b279593c9bed7fdb Mon Sep 17 00:00:00 2001
From: Aditya Khowal <108611217+AdityaKhowalGithub@users.noreply.github.com>
Date: Mon, 28 Apr 2025 01:06:14 +0000
Subject: [PATCH 1/2] update deduce_base to include error handingling

---
 src/stack_pr/cli.py | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/src/stack_pr/cli.py b/src/stack_pr/cli.py
index d068998..5c917a6 100755
--- a/src/stack_pr/cli.py
+++ b/src/stack_pr/cli.py
@@ -884,9 +884,24 @@ def deduce_base(args: CommonArgs) -> CommonArgs:
    """
     if args.base:
         return args
-    deduced_base = get_command_output(
-        ["git", "merge-base", args.head, f"{args.remote}/{args.target}"]
-    )
+
+    # Check if the remote branch exists
+    remote_branch = f"{args.remote}/{args.target}"
+    try:
+        run_shell_command(["git", "rev-parse", "--verify", remote_branch], quiet=True)
+    except SubprocessError:
+        error(f"Remote branch '{remote_branch}' does not exist. Please ensure the branch is available.")
+        sys.exit(1)
+
+    # Attempt to find the merge base
+    try:
+        deduced_base = get_command_output(
+            ["git", "merge-base", args.head, remote_branch]
+        )
+    except SubprocessError:
+        error(f"Failed to find a merge base between '{args.head}' and '{remote_branch}'.")
+        sys.exit(1)
+
     return CommonArgs(
         deduced_base,
         args.head,

From 29fbe69468e6b9b98fd22c66af11af54fb912e1a Mon Sep 17 00:00:00 2001
From: Aditya Khowal <108611217+AdityaKhowalGithub@users.noreply.github.com>
Date: Fri, 16 May 2025 03:37:06 +0000
Subject: [PATCH 2/2] formatted with ruff

---
 src/stack_pr/cli.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/stack_pr/cli.py b/src/stack_pr/cli.py
index 5c917a6..b5bbfd0 100755
--- a/src/stack_pr/cli.py
+++ b/src/stack_pr/cli.py
@@ -890,7 +890,9 @@ def deduce_base(args: CommonArgs) -> CommonArgs:
     try:
         run_shell_command(["git", "rev-parse", "--verify", remote_branch], quiet=True)
     except SubprocessError:
-        error(f"Remote branch '{remote_branch}' does not exist. Please ensure the branch is available.")
+        error(
+            f"Remote branch '{remote_branch}' does not exist. Please ensure the branch is available."
+        )
         sys.exit(1)
 
     # Attempt to find the merge base
@@ -899,7 +901,9 @@ def deduce_base(args: CommonArgs) -> CommonArgs:
             ["git", "merge-base", args.head, remote_branch]
         )
     except SubprocessError:
-        error(f"Failed to find a merge base between '{args.head}' and '{remote_branch}'.")
+        error(
+            f"Failed to find a merge base between '{args.head}' and '{remote_branch}'."
+        )
         sys.exit(1)
 
     return CommonArgs(