From 8546b114291a9cbee30c2d2fc26f023da8c97b52 Mon Sep 17 00:00:00 2001
From: jakelodwick <25925+jakelodwick@users.noreply.github.com>
Date: Tue, 24 Mar 2026 21:39:30 -0600
Subject: [PATCH 1/3] Cache hook state to skip redundant pyenv sh-activate
 calls

Mtime-based caching: stat the directory tree once per prompt (~2ms)
and skip full activation when nothing has changed.

- Compare PYENV_VERSION, VIRTUAL_ENV, PWD; shortcut when PYENV_VERSION matches
- Walk PWD to / for .python-version (stop at first; include broken symlinks)
- Path list built once on miss, stored as array (spaces in paths)
- Global version file skipped when local version active
- version-name hooks checked at init; if present, caching disabled
- Covers bash, zsh, and fish
---
 bin/pyenv-virtualenv-init | 110 +++++++++++++++++++++++++++++++++++++-
 test/init.bats            |  93 ++++++++++++++++++++++++++++++++
 test/test_helper.bash     |   8 +++
 3 files changed, 209 insertions(+), 2 deletions(-)

diff --git a/bin/pyenv-virtualenv-init b/bin/pyenv-virtualenv-init
index e12769a8..118ab205 100755
--- a/bin/pyenv-virtualenv-init
+++ b/bin/pyenv-virtualenv-init
@@ -9,6 +9,23 @@
 set -e
 [ -n "$PYENV_DEBUG" ] && set -x
 
+# Detect stat format for mtime: GNU uses -c %Y, BSD uses -f %m
+# -L follows symlinks: a symlinked .python-version reflects target changes
+if stat -L -c %Y / >/dev/null 2>&1; then
+  _stat_fmt="-L -c %Y"
+else
+  _stat_fmt="-L -f %m"
+fi
+
+# Check for version-name hooks at init time. Hooks can alter version
+# resolution in ways the mtime cache cannot track. If present, the hook
+# falls back to upstream behavior (no caching). Restart shell after
+# installing or removing pyenv plugins.
+_has_version_hooks=""
+if [ -n "$(pyenv hooks version-name 2>/dev/null)" ]; then
+  _has_version_hooks=1
+fi
+
 resolve_link() {
   $(type -p greadlink readlink | head -1) "$1"
 }
@@ -103,7 +120,8 @@ esac
 
 case "$shell" in
 fish )
-  cat <<EOS
+  if [ -n "$_has_version_hooks" ]; then
+    cat <<EOS
 function _pyenv_virtualenv_hook --on-event fish_prompt;
   set -l ret \$status
   if [ -n "\$VIRTUAL_ENV" ]
@@ -114,6 +132,50 @@ function _pyenv_virtualenv_hook --on-event fish_prompt;
   return \$ret
 end
 EOS
+  else
+    cat <<EOS
+function _pyenv_virtualenv_hook --on-event fish_prompt;
+  set -l ret \$status
+  if test "\$PYENV_VERSION" = "\$_PYENV_VH_VERSION" \\
+    -a "\$VIRTUAL_ENV" = "\$_PYENV_VH_VENV"
+    if test -n "\$PYENV_VERSION"
+      return \$ret
+    end
+    if test "\$PWD" = "\$_PYENV_VH_PWD" \\
+      -a "(stat ${_stat_fmt} \$_PYENV_VH_PATHS 2>/dev/null)" = "\$_PYENV_VH_MTIMES"
+      return \$ret
+    end
+  end
+  if [ -n "\$VIRTUAL_ENV" ]
+    pyenv activate --quiet; or pyenv deactivate --quiet; or true
+  else
+    pyenv activate --quiet; or true
+  end
+  set -g _PYENV_VH_PWD "\$PWD"
+  set -g _PYENV_VH_VERSION "\$PYENV_VERSION"
+  set -g _PYENV_VH_VENV "\$VIRTUAL_ENV"
+  set -l d "\$PWD"
+  set -l _pvh_found_local 0
+  set -g _PYENV_VH_PATHS
+  while true
+    if test -e "\$d/.python-version"; or test -L "\$d/.python-version"
+      set -g _PYENV_VH_PATHS \$_PYENV_VH_PATHS "\$d/.python-version"
+      set _pvh_found_local 1
+      break
+    end
+    set -g _PYENV_VH_PATHS \$_PYENV_VH_PATHS "\$d"
+    test "\$d" = "/"; and break
+    set d (string replace -r '/[^/]*\$' '' -- "\$d")
+    test -z "\$d"; and set d "/"
+  end
+  if test "\$_pvh_found_local" = "0"
+    set -g _PYENV_VH_PATHS \$_PYENV_VH_PATHS "\$PYENV_ROOT/version"
+  end
+  set -g _PYENV_VH_MTIMES (stat ${_stat_fmt} \$_PYENV_VH_PATHS 2>/dev/null)
+  return \$ret
+end
+EOS
+  fi
  ;;
 ksh )
   cat <<EOS
@@ -128,7 +190,8 @@ EOS
 esac
 
 if [[ "$shell" != "fish" ]]; then
-  cat <<EOS
+  if [ -n "$_has_version_hooks" ]; then
+    cat <<EOS
   local ret=\$?
   if [ -n "\${VIRTUAL_ENV-}" ]; then
     eval "\$(pyenv sh-activate --quiet || pyenv sh-deactivate --quiet || true)" || true
@@ -138,6 +201,49 @@ if [[ "$shell" != "fish" ]]; then
   return \$ret
 };
 EOS
+  else
+    cat <<EOS
+  local ret=\$?
+  # Cache: env vars checked once, path list and stat rebuilt on miss only
+  if [ "\${PYENV_VERSION-}" = "\${_PYENV_VH_VERSION-}" ] \\
+    && [ "\${VIRTUAL_ENV-}" = "\${_PYENV_VH_VENV-}" ]; then
+    if [ -n "\${PYENV_VERSION-}" ]; then
+      return \$ret
+    fi
+    if [ "\${PWD}" = "\${_PYENV_VH_PWD-}" ] \\
+      && [ "\$(stat ${_stat_fmt} "\${_PYENV_VH_PATHS[@]}" 2>/dev/null)" = "\${_PYENV_VH_MTIMES-}" ]; then
+      return \$ret
+    fi
+  fi
+  if [ -n "\${VIRTUAL_ENV-}" ]; then
+    eval "\$(pyenv sh-activate --quiet || pyenv sh-deactivate --quiet || true)" || true
+  else
+    eval "\$(pyenv sh-activate --quiet || true)" || true
+  fi
+  _PYENV_VH_PWD="\${PWD}"
+  _PYENV_VH_VERSION="\${PYENV_VERSION-}"
+  _PYENV_VH_VENV="\${VIRTUAL_ENV-}"
+  local _pvh_d="\${PWD}" _pvh_found_local=0
+  _PYENV_VH_PATHS=()
+  while :; do
+    if [ -e "\${_pvh_d}/.python-version" ] || [ -L "\${_pvh_d}/.python-version" ]; then
+      _PYENV_VH_PATHS+=("\${_pvh_d}/.python-version")
+      _pvh_found_local=1
+      break
+    fi
+    _PYENV_VH_PATHS+=("\${_pvh_d}")
+    [ "\${_pvh_d}" = "/" ] && break
+    _pvh_d="\${_pvh_d%/*}"
+    [ -z "\${_pvh_d}" ] && _pvh_d="/"
+  done
+  if [ "\${_pvh_found_local}" = "0" ]; then
+    _PYENV_VH_PATHS+=("\${PYENV_ROOT}/version")
+  fi
+  _PYENV_VH_MTIMES="\$(stat ${_stat_fmt} "\${_PYENV_VH_PATHS[@]}" 2>/dev/null)"
+  return \$ret
+};
+EOS
+  fi
 
   case "$shell" in
   bash )
diff --git a/test/init.bats b/test/init.bats
index 85f2b423..ff4c041a 100644
--- a/test/init.bats
+++ b/test/init.bats
@@ -54,11 +54,42 @@ export PATH="${TMP}/pyenv/plugins/pyenv-virtualenv/shims:\${PATH}";
 export PYENV_VIRTUALENV_INIT=1;
 _pyenv_virtualenv_hook() {
   local ret=\$?
+  # Cache: env vars checked once, path list and stat rebuilt on miss only
+  if [ "\${PYENV_VERSION-}" = "\${_PYENV_VH_VERSION-}" ] \\
+    && [ "\${VIRTUAL_ENV-}" = "\${_PYENV_VH_VENV-}" ]; then
+    if [ -n "\${PYENV_VERSION-}" ]; then
+      return \$ret
+    fi
+    if [ "\${PWD}" = "\${_PYENV_VH_PWD-}" ] \\
+      && [ "\$(stat ${_stat_fmt} "\${_PYENV_VH_PATHS[@]}" 2>/dev/null)" = "\${_PYENV_VH_MTIMES-}" ]; then
+      return \$ret
+    fi
+  fi
   if [ -n "\${VIRTUAL_ENV-}" ]; then
     eval "\$(pyenv sh-activate --quiet || pyenv sh-deactivate --quiet || true)" || true
   else
     eval "\$(pyenv sh-activate --quiet || true)" || true
   fi
+  _PYENV_VH_PWD="\${PWD}"
+  _PYENV_VH_VERSION="\${PYENV_VERSION-}"
+  _PYENV_VH_VENV="\${VIRTUAL_ENV-}"
+  local _pvh_d="\${PWD}" _pvh_found_local=0
+  _PYENV_VH_PATHS=()
+  while :; do
+    if [ -e "\${_pvh_d}/.python-version" ] || [ -L "\${_pvh_d}/.python-version" ]; then
+      _PYENV_VH_PATHS+=("\${_pvh_d}/.python-version")
+      _pvh_found_local=1
+      break
+    fi
+    _PYENV_VH_PATHS+=("\${_pvh_d}")
+    [ "\${_pvh_d}" = "/" ] && break
+    _pvh_d="\${_pvh_d%/*}"
+    [ -z "\${_pvh_d}" ] && _pvh_d="/"
+  done
+  if [ "\${_pvh_found_local}" = "0" ]; then
+    _PYENV_VH_PATHS+=("\${PYENV_ROOT}/version")
+  fi
+  _PYENV_VH_MTIMES="\$(stat ${_stat_fmt} "\${_PYENV_VH_PATHS[@]}" 2>/dev/null)"
   return \$ret
 };
 if ! [[ "\${PROMPT_COMMAND-}" =~ _pyenv_virtualenv_hook ]]; then
@@ -78,11 +109,42 @@ set -gx PATH '${TMP}/pyenv/plugins/pyenv-virtualenv/shims' \$PATH;
 set -gx PYENV_VIRTUALENV_INIT 1;
 function _pyenv_virtualenv_hook --on-event fish_prompt;
   set -l ret \$status
+  if test "\$PYENV_VERSION" = "\$_PYENV_VH_VERSION" \\
+    -a "\$VIRTUAL_ENV" = "\$_PYENV_VH_VENV"
+    if test -n "\$PYENV_VERSION"
+      return \$ret
+    end
+    if test "\$PWD" = "\$_PYENV_VH_PWD" \\
+      -a "(stat ${_stat_fmt} \$_PYENV_VH_PATHS 2>/dev/null)" = "\$_PYENV_VH_MTIMES"
+      return \$ret
+    end
+  end
   if [ -n "\$VIRTUAL_ENV" ]
     pyenv activate --quiet; or pyenv deactivate --quiet; or true
   else
     pyenv activate --quiet; or true
   end
+  set -g _PYENV_VH_PWD "\$PWD"
+  set -g _PYENV_VH_VERSION "\$PYENV_VERSION"
+  set -g _PYENV_VH_VENV "\$VIRTUAL_ENV"
+  set -l d "\$PWD"
+  set -l _pvh_found_local 0
+  set -g _PYENV_VH_PATHS
+  while true
+    if test -e "\$d/.python-version"; or test -L "\$d/.python-version"
+      set -g _PYENV_VH_PATHS \$_PYENV_VH_PATHS "\$d/.python-version"
+      set _pvh_found_local 1
+      break
+    end
+    set -g _PYENV_VH_PATHS \$_PYENV_VH_PATHS "\$d"
+    test "\$d" = "/"; and break
+    set d (string replace -r '/[^/]*\$' '' -- "\$d")
+    test -z "\$d"; and set d "/"
+  end
+  if test "\$_pvh_found_local" = "0"
+    set -g _PYENV_VH_PATHS \$_PYENV_VH_PATHS "\$PYENV_ROOT/version"
+  end
+  set -g _PYENV_VH_MTIMES (stat ${_stat_fmt} \$_PYENV_VH_PATHS 2>/dev/null)
   return \$ret
 end
 EOS
@@ -97,11 +159,42 @@ export PATH="${TMP}/pyenv/plugins/pyenv-virtualenv/shims:\${PATH}";
 export PYENV_VIRTUALENV_INIT=1;
 _pyenv_virtualenv_hook() {
   local ret=\$?
+  # Cache: env vars checked once, path list and stat rebuilt on miss only
+  if [ "\${PYENV_VERSION-}" = "\${_PYENV_VH_VERSION-}" ] \\
+    && [ "\${VIRTUAL_ENV-}" = "\${_PYENV_VH_VENV-}" ]; then
+    if [ -n "\${PYENV_VERSION-}" ]; then
+      return \$ret
+    fi
+    if [ "\${PWD}" = "\${_PYENV_VH_PWD-}" ] \\
+      && [ "\$(stat ${_stat_fmt} "\${_PYENV_VH_PATHS[@]}" 2>/dev/null)" = "\${_PYENV_VH_MTIMES-}" ]; then
+      return \$ret
+    fi
+  fi
   if [ -n "\${VIRTUAL_ENV-}" ]; then
     eval "\$(pyenv sh-activate --quiet || pyenv sh-deactivate --quiet || true)" || true
   else
     eval "\$(pyenv sh-activate --quiet || true)" || true
   fi
+  _PYENV_VH_PWD="\${PWD}"
+  _PYENV_VH_VERSION="\${PYENV_VERSION-}"
+  _PYENV_VH_VENV="\${VIRTUAL_ENV-}"
+  local _pvh_d="\${PWD}" _pvh_found_local=0
+  _PYENV_VH_PATHS=()
+  while :; do
+    if [ -e "\${_pvh_d}/.python-version" ] || [ -L "\${_pvh_d}/.python-version" ]; then
+      _PYENV_VH_PATHS+=("\${_pvh_d}/.python-version")
+      _pvh_found_local=1
+      break
+    fi
+    _PYENV_VH_PATHS+=("\${_pvh_d}")
+    [ "\${_pvh_d}" = "/" ] && break
+    _pvh_d="\${_pvh_d%/*}"
+    [ -z "\${_pvh_d}" ] && _pvh_d="/"
+  done
+  if [ "\${_pvh_found_local}" = "0" ]; then
+    _PYENV_VH_PATHS+=("\${PYENV_ROOT}/version")
+  fi
+  _PYENV_VH_MTIMES="\$(stat ${_stat_fmt} "\${_PYENV_VH_PATHS[@]}" 2>/dev/null)"
   return \$ret
 };
 typeset -g -a precmd_functions
diff --git a/test/test_helper.bash b/test/test_helper.bash
index 3d179c9a..7d927d59 100644
--- a/test/test_helper.bash
+++ b/test/test_helper.bash
@@ -1,4 +1,12 @@
 export TMP="$BATS_TEST_DIRNAME/tmp"
+
+# Detect stat format for mtime: GNU uses -c %Y, BSD uses -f %m
+# Must match the detection in bin/pyenv-virtualenv-init
+if stat -L -c %Y / >/dev/null 2>&1; then
+  _stat_fmt="-L -c %Y"
+else
+  _stat_fmt="-L -f %m"
+fi
 export PS4='+(${BASH_SOURCE}:${LINENO}): ${FUNCNAME[0]:+${FUNCNAME[0]}(): }'
 
 PATH=/usr/bin:/usr/sbin:/bin:/sbin

From 6d048007e87aa3caa0873088e1fc86e7db99ee91 Mon Sep 17 00:00:00 2001
From: Ivan Pozdeev <ivan.pozdeev.gm@gmail.com>
Date: Wed, 25 Mar 2026 20:41:28 +0300
Subject: [PATCH 2/3] For broken .python-version symlinks, remember them but
 keep going

---
 bin/pyenv-virtualenv-init | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/bin/pyenv-virtualenv-init b/bin/pyenv-virtualenv-init
index 118ab205..138fb48e 100755
--- a/bin/pyenv-virtualenv-init
+++ b/bin/pyenv-virtualenv-init
@@ -158,12 +158,15 @@ function _pyenv_virtualenv_hook --on-event fish_prompt;
   set -l _pvh_found_local 0
   set -g _PYENV_VH_PATHS
   while true
-    if test -e "\$d/.python-version"; or test -L "\$d/.python-version"
+    if test -f "\$d/.python-version"; or test -L "\$d/.python-version"
       set -g _PYENV_VH_PATHS \$_PYENV_VH_PATHS "\$d/.python-version"
-      set _pvh_found_local 1
-      break
+      if test -f "\$d/.python-version" 
+        set _pvh_found_local 1
+        break
+      end
+    else
+      set -g _PYENV_VH_PATHS \$_PYENV_VH_PATHS "\$d"
     end
-    set -g _PYENV_VH_PATHS \$_PYENV_VH_PATHS "\$d"
     test "\$d" = "/"; and break
     set d (string replace -r '/[^/]*\$' '' -- "\$d")
     test -z "\$d"; and set d "/"
@@ -226,12 +229,15 @@ EOS
   local _pvh_d="\${PWD}" _pvh_found_local=0
   _PYENV_VH_PATHS=()
   while :; do
-    if [ -e "\${_pvh_d}/.python-version" ] || [ -L "\${_pvh_d}/.python-version" ]; then
+    if [ -f "\${_pvh_d}/.python-version" ] || [ -L "\${_pvh_d}/.python-version" ]; then
       _PYENV_VH_PATHS+=("\${_pvh_d}/.python-version")
-      _pvh_found_local=1
-      break
+      if [ -f "\${_pvh_d}/.python-version" ]; then 
+        _pvh_found_local=1
+        break
+      fi
+    else
+      _PYENV_VH_PATHS+=("\${_pvh_d}")
     fi
-    _PYENV_VH_PATHS+=("\${_pvh_d}")
     [ "\${_pvh_d}" = "/" ] && break
     _pvh_d="\${_pvh_d%/*}"
     [ -z "\${_pvh_d}" ] && _pvh_d="/"

From 27500cd3df0b025698f6939eaf9b317fabfbd2ce Mon Sep 17 00:00:00 2001
From: Ivan Pozdeev <vano@mail.mipt.ru>
Date: Wed, 25 Mar 2026 20:52:30 +0300
Subject: [PATCH 3/3] adjust tests

---
 test/init.bats | 33 +++++++++++++++++++++------------
 1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/test/init.bats b/test/init.bats
index ff4c041a..2aacc8fc 100644
--- a/test/init.bats
+++ b/test/init.bats
@@ -76,12 +76,15 @@ _pyenv_virtualenv_hook() {
   local _pvh_d="\${PWD}" _pvh_found_local=0
   _PYENV_VH_PATHS=()
   while :; do
-    if [ -e "\${_pvh_d}/.python-version" ] || [ -L "\${_pvh_d}/.python-version" ]; then
+    if [ -f "\${_pvh_d}/.python-version" ] || [ -L "\${_pvh_d}/.python-version" ]; then
       _PYENV_VH_PATHS+=("\${_pvh_d}/.python-version")
-      _pvh_found_local=1
-      break
+      if [ -f "\${_pvh_d}/.python-version" ]; then 
+        _pvh_found_local=1
+        break
+      fi
+    else
+      _PYENV_VH_PATHS+=("\${_pvh_d}")
     fi
-    _PYENV_VH_PATHS+=("\${_pvh_d}")
     [ "\${_pvh_d}" = "/" ] && break
     _pvh_d="\${_pvh_d%/*}"
     [ -z "\${_pvh_d}" ] && _pvh_d="/"
@@ -131,12 +134,15 @@ function _pyenv_virtualenv_hook --on-event fish_prompt;
   set -l _pvh_found_local 0
   set -g _PYENV_VH_PATHS
   while true
-    if test -e "\$d/.python-version"; or test -L "\$d/.python-version"
+    if test -f "\$d/.python-version"; or test -L "\$d/.python-version"
       set -g _PYENV_VH_PATHS \$_PYENV_VH_PATHS "\$d/.python-version"
-      set _pvh_found_local 1
-      break
+      if test -f "\$d/.python-version" 
+        set _pvh_found_local 1
+        break
+      end
+    else
+      set -g _PYENV_VH_PATHS \$_PYENV_VH_PATHS "\$d"
     end
-    set -g _PYENV_VH_PATHS \$_PYENV_VH_PATHS "\$d"
     test "\$d" = "/"; and break
     set d (string replace -r '/[^/]*\$' '' -- "\$d")
     test -z "\$d"; and set d "/"
@@ -181,12 +187,15 @@ _pyenv_virtualenv_hook() {
   local _pvh_d="\${PWD}" _pvh_found_local=0
   _PYENV_VH_PATHS=()
   while :; do
-    if [ -e "\${_pvh_d}/.python-version" ] || [ -L "\${_pvh_d}/.python-version" ]; then
+    if [ -f "\${_pvh_d}/.python-version" ] || [ -L "\${_pvh_d}/.python-version" ]; then
       _PYENV_VH_PATHS+=("\${_pvh_d}/.python-version")
-      _pvh_found_local=1
-      break
+      if [ -f "\${_pvh_d}/.python-version" ]; then 
+        _pvh_found_local=1
+        break
+      fi
+    else
+      _PYENV_VH_PATHS+=("\${_pvh_d}")
     fi
-    _PYENV_VH_PATHS+=("\${_pvh_d}")
     [ "\${_pvh_d}" = "/" ] && break
     _pvh_d="\${_pvh_d%/*}"
     [ -z "\${_pvh_d}" ] && _pvh_d="/"