main: work around the issue that WSL clears "/tmp" after Bash starts

ble.pp

@@ -1589,11 +1589,15 @@ function ble/base/initialize-base-directory {
 ##   2. /tmp/blesh/$UID を作成可能ならば、それを使う。
 ##   3. $_ble_base/tmp/$UID を使う。
 ##
+_ble_base_is_wsl_status=
 function ble/base/initialize-runtime-directory/.is-wsl {
+  [[ $_ble_base_is_wsl_status ]] && return "$_ble_base_is_wsl_status"
+  _ble_base_is_wsl_status=1
   [[ -d /usr/lib/wsl/lib && -r /proc/version ]] || return 1
   local kernel_version
   ble/bash/read kernel_version < /proc/version || return 1
-  [[ $kernel_version == *-microsoft-* ]]
+  [[ $kernel_version == *-microsoft-* ]] || return 1
+  _ble_base_is_wsl_status=0
 }
 function ble/base/initialize-runtime-directory/.xdg {
   local runtime_dir=
@@ -1633,6 +1637,12 @@ function ble/base/initialize-runtime-directory/.xdg {
 function ble/base/initialize-runtime-directory/.tmp {
   [[ -r /tmp && -w /tmp && -x /tmp ]] || return 1
 
+  # Note: WSL seems to clear /tmp after the first instance of Bash starts,
+  # which causes a problem of missing /tmp after blesh's initialization.
+  # https://github.com/microsoft/WSL/issues/8441#issuecomment-1139434972
+  # https://github.com/akinomyoga/ble.sh/discussions/462
+  ble/base/initialize-runtime-directory/.is-wsl && return 1
+
   local tmp_dir=/tmp/blesh
   if [[ ! -d $tmp_dir ]]; then
     [[ ! -e $tmp_dir && -h $tmp_dir ]] && ble/bin/rm -f "$tmp_dir"
@@ -1649,18 +1659,40 @@ function ble/base/initialize-runtime-directory/.tmp {
 
   ble/base/.create-user-directory _ble_base_run "$tmp_dir/$UID"
 }
-function ble/base/initialize-runtime-directory {
-  ble/base/initialize-runtime-directory/.xdg && return 0
-  ble/base/initialize-runtime-directory/.tmp && return 0
-
-  # fallback
+function ble/base/initialize-runtime-directory/.base {
   local tmp_dir=$_ble_base/run
   if [[ ! -d $tmp_dir ]]; then
     ble/bin/mkdir -p "$tmp_dir" || return 1
     ble/bin/chmod a+rwxt "$tmp_dir" || return 1
   fi
   ble/base/.create-user-directory _ble_base_run "$tmp_dir/${USER:-$UID}@$HOSTNAME"
 }
+function ble/base/initialize-runtime-directory/.home {
+  local cache_dir=${XDG_CACHE_HOME:-$HOME/.cache}
+  if [[ ! -d $cache_dir ]]; then
+    if [[ $XDG_CACHE_HOME ]]; then
+      ble/util/print "ble.sh: XDG_CACHE_HOME='$XDG_CACHE_HOME' is not a directory." >&2
+      return 1
+    else
+      ble/bin/mkdir -p "$cache_dir" || return 1
+    fi
+  fi
+  if ! [[ -r $cache_dir && -w $cache_dir && -x $cache_dir ]]; then
+    if [[ $XDG_CACHE_HOME ]]; then
+      ble/util/print "ble.sh: XDG_CACHE_HOME='$XDG_CACHE_HOME' doesn't have a proper permission." >&2
+    else
+      ble/util/print "ble.sh: '$cache_dir' doesn't have a proper permission." >&2
+    fi
+    return 1
+  fi
+  ble/base/.create-user-directory _ble_base_run "$cache_dir/blesh/run"
+}
+function ble/base/initialize-runtime-directory {
+  ble/base/initialize-runtime-directory/.xdg && return 0
+  ble/base/initialize-runtime-directory/.tmp && return 0
+  ble/base/initialize-runtime-directory/.base && return 0
+  ble/base/initialize-runtime-directory/.home
+}
 if ! ble/base/initialize-runtime-directory; then
   ble/util/print "ble.sh: failed to initialize \$_ble_base_run." >&2
   ble/base/clear-version-variables

docs/ChangeLog.md

@@ -158,6 +158,7 @@
 - term: detect iTerm2 `#D2224` xxxxxxxx
 - mandb: support man page format of `rg` (requested by pallaswept) `#D2225` xxxxxxxx
 - mandb: restore ASCII hyphens from Unicode hyphens before analysis (reported by pallaswept) `#D2230` xxxxxxxx
+- main: work around the issue WSL clears `/tmp` after Bash starts (reported by LeonardoMor) `#D2235` xxxxxxxx
 
 ## Contrib
 

note.txt

@@ -7394,6 +7394,14 @@ bash_tips
 
 2024-07-01
 
+  * main: work around the issue that WSL clears "/tmp" after Bash starts (reported by LeonardoMor) [#D2235]
+    https://github.com/akinomyoga/ble.sh/discussions/462
+    https://github.com/microsoft/WSL/issues/8441#issuecomment-1139434972
+
+    既に WSL で報告されている様だ。gitstatus が /tmp を作った後に中身が消去され
+    ているという問題。報告されていて romkatv は何度も mention しているが、WSL
+    での issue は閉じられて無視されている。
+
   * test: skip tests on "ble/test/chdir" failure [#D2234]
 
     何らかの理由で ble/test/chdir に失敗した時 (例えば permission の問題でディ