display the new rustc version when rustc is upgraded; fixes #365

internal/p10k.zsh

@@ -2179,9 +2179,7 @@ instant_prompt_root_indicator() { prompt_root_indicator; }
 ################################################################
 # Segment to display Rust version number
 prompt_rust_version() {
-  _p9k_cached_cmd_stdout rustc --version || return
+  (( $+commands[rustc] )) || return
-  local v=${${_p9k_ret#rustc }%% *}
-  [[ -n $v ]] || return
   if (( _POWERLEVEL9K_RUST_VERSION_PROJECT_ONLY )); then
     local dir=$_p9k_pwd_a
     while true; do
@@ -2190,6 +2188,25 @@ prompt_rust_version() {
       dir=${dir:h}
     done
   fi
+  local rustc=$commands[rustc] so
+  if (( $+commands[ldd] )); then
+    if _p9k_cache_stat_get $0_so $rustc; then
+      so=$_p9k_cache_val[1]
+    else
+      local line match
+      for line in "${(@f)$(ldd $rustc 2>/dev/null)}"; do
+        [[ $line == (#b)[[:space:]]#librustc_driver[^[:space:]]#.so' => '(*)' (0x'[[:xdigit:]]#')' ]] || continue
+        so=$match[1]
+        break
+      done
+      _p9k_cache_stat_set "$so"
+    fi
+  fi
+  if ! _p9k_cache_stat_get $0_v $rustc $so; then
+    _p9k_cache_stat_set "$($rustc --version 2>/dev/null)"
+  fi
+  local v=${${_p9k_cache_val[1]#rustc }%% *}
+  [[ -n $v ]] || return
   _p9k_prompt_segment "$0" "darkorange" "$_p9k_color1" 'RUST_ICON' 0 '' "${v//\%/%%}"
 }
 
@@ -5413,7 +5430,7 @@ _p9k_must_init() {
     [[ $sig == $_p9k__param_sig ]] && return 1
     _p9k_deinit
   fi
-  _p9k__param_pat=$'v13\1'${ZSH_VERSION}$'\1'${ZSH_PATCHLEVEL}$'\1'
+  _p9k__param_pat=$'v14\1'${ZSH_VERSION}$'\1'${ZSH_PATCHLEVEL}$'\1'
   _p9k__param_pat+=$'${#parameters[(I)POWERLEVEL9K_*]}\1${(%):-%n%#}\1$GITSTATUS_LOG_LEVEL\1'
   _p9k__param_pat+=$'$GITSTATUS_ENABLE_LOGGING\1$GITSTATUS_DAEMON\1$GITSTATUS_NUM_THREADS\1'
   _p9k__param_pat+=$'$DEFAULT_USER\1${ZLE_RPROMPT_INDENT:-1}\1$P9K_SSH\1$__p9k_ksh_arrays'