From 07e9fb58f64482dcc5ff6ebe2854fd4d70073e8d Mon Sep 17 00:00:00 2001
From: Samson Yeung <samson_gh@onepatchdown.net>
Date: Thu, 29 Sep 2022 12:56:22 -0700
Subject: [PATCH] Avoid a specific case where `conda env update` hangs.
 (#11818)

When using an environment.yml that asks pip to clone a git repo and
that path exists, pip will ask for user input. As we are not in a
context to provide such, tell pip what to do so it doesn't hang on
waiting for user input.
---
 conda_env/installers/pip.py |  3 ++-
 news/11818-conda-hang       | 21 +++++++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 news/11818-conda-hang

diff --git a/conda_env/installers/pip.py b/conda_env/installers/pip.py
index ae882bff53f..aa259a91c45 100644
--- a/conda_env/installers/pip.py
+++ b/conda_env/installers/pip.py
@@ -48,7 +48,8 @@ def _pip_install_via_requirements(prefix, specs, args, *_, **kwargs):
         requirements.write('\n'.join(specs))
         requirements.close()
         # pip command line...
-        pip_cmd = ['install', '-U', '-r', requirements.name]
+        # see https://pip.pypa.io/en/stable/cli/pip/#exists-action-option
+        pip_cmd = ['install', '-U', '-r', requirements.name, '--exists-action=b']
         stdout, stderr = pip_subprocess(pip_cmd, prefix, cwd=pip_workdir)
     finally:
         # Win/Appveyor does not like it if we use context manager + delete=True.
diff --git a/news/11818-conda-hang b/news/11818-conda-hang
new file mode 100644
index 00000000000..57976e57aaf
--- /dev/null
+++ b/news/11818-conda-hang
@@ -0,0 +1,21 @@
+### Enhancements
+
+* <news item>
+
+### Bug fixes
+
+* `conda env update` would ask for user input and hang when working with pip
+installs of git repos and the repo was previously checked out. Tell pip not to
+ask for user input for that case.  (#11818)
+
+### Deprecations
+
+* <news item>
+
+### Docs
+
+* <news item>
+
+### Other
+
+* <news item>