home-manager: handle missing per-user profiles directory

Specifically, if the global per-user profiles path do not exist and we
cannot create it during the activation, then place our profile in the
Home Manager data directory. We prefer to use the global location,
though, since it makes it visible to `nix-collect-garbage`.

This is intended to improve compatibility with Nix version 2.14 and
later, which no longer creates the per-user directories.

Also, use the Home Manager data directory to manage the gcroot for the
current generation. It does not have to sit in the global per-user
gcroots directory since it should never be eligible for GC.

home-manager/home-manager

@@ -19,7 +19,7 @@ function removeByName() {
 }
 
 function setNixProfileCommands() {
- if [[ -e ~/.nix-profile/manifest.json ]] ; then
+ if [[ -e $HOME/.nix-profile/manifest.json ]] ; then
  LIST_OUTPATH_CMD="nix profile list"
  REMOVE_CMD="removeByName"
  else
@@ -93,6 +93,23 @@ function setHomeManagerNixPath() {
  done
 }
 
+# Sets some useful Home Manager related paths as global read-only variables.
+function setHomeManagerPathVariables() {
+ declare -r nixStateDir="${NIX_STATE_DIR:-/nix/var/nix}"
+ declare -r globalProfilesDir="$nixStateDir/profiles/per-user/$USER"
+ declare -r globalGcrootsDir="$nixStateDir/gcroots/per-user/$USER"
+
+ declare -gr HM_DATA_HOME="${XDG_DATA_HOME:-$HOME/.local/share}/home-manager"
+ declare -gr HM_STATE_DIR="${XDG_STATE_HOME:-$HOME/.local/state}/home-manager"
+ declare -gr HM_GCROOT_LEGACY_PATH="$globalGcrootsDir/current-home"
+
+ if [[ -d "$globalProfilesDir" ]]; then
+ declare -gr HM_PROFILE_DIR="$globalProfilesDir"
+ else
+ declare -gr HM_PROFILE_DIR="$HM_STATE_DIR/profiles"
+ fi
+}
+
 function setFlakeAttribute() {
  local configFlake="${XDG_CONFIG_HOME:-$HOME/.config}/nixpkgs/flake.nix"
  if [[ -z $FLAKE_ARG && ! -v HOME_MANAGER_CONFIG && -e "$configFlake" ]]; then
@@ -339,7 +356,7 @@ function doListGens() {
  color="always"
  fi
 
- pushd "$NIX_STATE_DIR/profiles/per-user/$USER" > /dev/null
+ pushd "$HM_PROFILE_DIR" > /dev/null
  # shellcheck disable=2012
  ls --color=$color -gG --time-style=long-iso --sort time home-manager-*-link \
  | cut -d' ' -f 4- \
@@ -352,7 +369,7 @@ function doListGens() {
 function doRmGenerations() {
  setVerboseAndDryRun
 
- pushd "$NIX_STATE_DIR/profiles/per-user/$USER" > /dev/null
+ pushd "$HM_PROFILE_DIR" > /dev/null
 
  for generationId in "$@"; do
  local linkName="home-manager-$generationId-link"
@@ -370,17 +387,10 @@ function doRmGenerations() {
  popd > /dev/null
 }
 
-function doRmAllGenerations() {
- $DRY_RUN_CMD rm $VERBOSE_ARG \
- "$NIX_STATE_DIR/profiles/per-user/$USER/home-manager"*
-}
-
 function doExpireGenerations() {
- local profileDir="$NIX_STATE_DIR/profiles/per-user/$USER"
-
  local generations
  generations="$( \
- find "$profileDir" -name 'home-manager-*-link' -not -newermt "$1" \
+ find "$HM_PROFILE_DIR" -name 'home-manager-*-link' -not -newermt "$1" \
  | sed 's/^.*-\([0-9]*\)-link$/\1/' \
  )"
 
@@ -482,6 +492,7 @@ function doUninstall() {
  read -r -n 1 -p "$(_i 'Really uninstall Home Manager?') [y/n] " confirmation
  echo
 
+ # shellcheck disable=2086
  case $confirmation in
  y|Y)
  _i "Switching to empty Home Manager configuration..."
@@ -493,30 +504,26 @@ function doUninstall() {
  doSwitch
  $DRY_RUN_CMD $REMOVE_CMD home-manager-path || true
  rm "$HOME_MANAGER_CONFIG"
- $DRY_RUN_CMD rm $VERBOSE_ARG -r \
- "${XDG_DATA_HOME:-$HOME/.local/share}/home-manager"
- $DRY_RUN_CMD rm $VERBOSE_ARG \
- "$NIX_STATE_DIR/gcroots/per-user/$USER/current-home"
- ;;
- *)
- _i "Yay!"
- exit 0
- ;;
- esac
 
- local deleteProfiles
- read -r -n 1 \
- -p "$(_i 'Remove all Home Manager generations?') [y/n] " \
- deleteProfiles
- echo
+ if [[ -e $HM_DATA_HOME ]]; then
+ $DRY_RUN_CMD rm $VERBOSE_ARG -r "$HM_DATA_HOME"
+ fi
 
- case $deleteProfiles in
- y|Y)
- doRmAllGenerations
- _i 'All generations are now eligible for garbage collection.'
+ if [[ -e $HM_PROFILE_DIR ]]; then
+ $DRY_RUN_CMD rm $VERBOSE_ARG "$HM_PROFILE_DIR/home-manager"*
+ fi
+
+ if [[ -e $HM_GCROOT_LEGACY_PATH ]]; then
+ $DRY_RUN_CMD rm $VERBOSE_ARG "$HM_GCROOT_LEGACY_PATH"
+ fi
+
+ if [[ -e $HM_STATE_DIR ]]; then
+ $DRY_RUN_CMD rm $VERBOSE_ARG -r "$HM_STATE_DIR"
+ fi
  ;;
  *)
- _i 'Leaving generations but they may still be garbage collected.'
+ _i "Yay!"
+ exit 0
  ;;
  esac
 
@@ -591,8 +598,6 @@ function doHelp() {
  echo " uninstall Remove Home Manager"
 }
 
-readonly NIX_STATE_DIR="${NIX_STATE_DIR:-/nix/var/nix}"
-
 EXTRA_NIX_PATH=()
 HOME_MANAGER_CONFIG_ATTRIBUTE=""
 PASSTHROUGH_OPTS=()
@@ -601,6 +606,7 @@ COMMAND_ARGS=()
 FLAKE_ARG=""
 
 setHomeManagerNixPath
+setHomeManagerPathVariables
 
 while [[ $# -gt 0 ]]; do
  opt="$1"

home-manager/po/home-manager.pot

@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: Home Manager\n"
 "Report-Msgid-Bugs-To: https://github.com/nix-community/home-manager/issues\n"
-"POT-Creation-Date: 2022-03-26 15:08+0100\n"
+"POT-Creation-Date: 2023-03-07 23:23+0100\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -26,15 +26,15 @@ msgstr ""
 msgid "No configuration file found. Please create one at %s"
 msgstr ""
 
-#: home-manager/home-manager:122
+#: home-manager/home-manager:146
 msgid "Can't inspect options of a flake configuration"
 msgstr ""
 
-#: home-manager/home-manager:162
+#: home-manager/home-manager:185
 msgid "Can't instantiate a flake configuration"
 msgstr ""
 
-#: home-manager/home-manager:237
+#: home-manager/home-manager:258
 msgid ""
 "There is %d unread and relevant news item.\n"
 "Read it by running the command \"%s news\"."
@@ -44,92 +44,80 @@ msgid_plural ""
 msgstr[0] ""
 msgstr[1] ""
 
-#: home-manager/home-manager:251
+#: home-manager/home-manager:272
 msgid "Unknown \"news.display\" setting \"%s\"."
 msgstr ""
 
-#: home-manager/home-manager:258
+#: home-manager/home-manager:279
 #, sh-format
 msgid "Please set the $EDITOR environment variable"
 msgstr ""
 
-#: home-manager/home-manager:273
+#: home-manager/home-manager:294
 msgid "Cannot run build in read-only directory"
 msgstr ""
 
-#: home-manager/home-manager:355
+#: home-manager/home-manager:378
 msgid "No generation with ID %s"
 msgstr ""
 
-#: home-manager/home-manager:357
+#: home-manager/home-manager:380
 msgid "Cannot remove the current generation %s"
 msgstr ""
 
-#: home-manager/home-manager:359
+#: home-manager/home-manager:382
 msgid "Removing generation %s"
 msgstr ""
 
-#: home-manager/home-manager:385
+#: home-manager/home-manager:401
 msgid "No generations to expire"
 msgstr ""
 
-#: home-manager/home-manager:396
+#: home-manager/home-manager:412
 msgid "No home-manager packages seem to be installed."
 msgstr ""
 
-#: home-manager/home-manager:453
+#: home-manager/home-manager:469
 msgid "Unknown argument %s"
 msgstr ""
 
-#: home-manager/home-manager:469
+#: home-manager/home-manager:485
 msgid "This will remove Home Manager from your system."
 msgstr ""
 
-#: home-manager/home-manager:472
+#: home-manager/home-manager:488
 msgid "This is a dry run, nothing will actually be uninstalled."
 msgstr ""
 
-#: home-manager/home-manager:476
+#: home-manager/home-manager:492
 msgid "Really uninstall Home Manager?"
 msgstr ""
 
-#: home-manager/home-manager:481
+#: home-manager/home-manager:498
 msgid "Switching to empty Home Manager configuration..."
 msgstr ""
 
-#: home-manager/home-manager:493
+#: home-manager/home-manager:521
 msgid "Yay!"
 msgstr ""
 
-#: home-manager/home-manager:500
-msgid "Remove all Home Manager generations?"
-msgstr ""
-
-#: home-manager/home-manager:507
-msgid "All generations are now eligible for garbage collection."
-msgstr ""
-
-#: home-manager/home-manager:510
-msgid "Leaving generations but they may still be garbage collected."
-msgstr ""
-
-#: home-manager/home-manager:514
+#: home-manager/home-manager:526
 msgid "Home Manager is uninstalled but your home.nix is left untouched."
 msgstr ""
 
-#: home-manager/home-manager:673
+#: home-manager/home-manager:691
 msgid "%s: unknown option '%s'"
 msgstr ""
 
-#: home-manager/home-manager:674
+#: home-manager/home-manager:692
 msgid "Run '%s --help' for usage help"
 msgstr ""
 
-#: home-manager/home-manager:708
+#: home-manager/home-manager:726
 msgid "expire-generations expects one argument, got %d."
 msgstr ""
 
-#: home-manager/home-manager:730
+#: home-manager/home-manager:748
 msgid "Unknown command: %s"
 msgstr ""
 

modules/files.nix

@@ -272,7 +272,10 @@ in
  $DRY_RUN_CMD nix-env $VERBOSE_ARG --profile "$genProfilePath" --set "$newGenPath"
  fi
 
- $DRY_RUN_CMD ln -Tsf $VERBOSE_ARG "$newGenPath" "$newGenGcPath"
+ $DRY_RUN_CMD nix-store --realise "$newGenPath" --add-root "$newGenGcPath" > "$DRY_RUN_NULL"
+ if [[ -e "$legacyGenGcPath" ]]; then
+ $DRY_RUN_CMD rm $VERBOSE_ARG "$legacyGenGcPath"
+ fi
  else
  _i "No change so reusing latest profile generation %s" "$oldGenNum"
  fi

modules/home-environment.nix

@@ -584,7 +584,7 @@ in
  if config.submoduleSupport.externalPackageInstall
  then
  ''
- if [[ -e "$nixProfilePath"/manifest.json ]] ; then
+ if [[ -e $HOME/.nix-profile/manifest.json ]] ; then
  nix profile list \
  | { grep 'home-manager-path$' || test $? = 1; } \
  | cut -d ' ' -f 4 \
@@ -608,7 +608,7 @@ in
  $DRY_RUN_CMD $oldNix profile install $1
  }
 
- if [[ -e "$nixProfilePath"/manifest.json ]] ; then
+ if [[ -e $HOME/.nix-profile/manifest.json ]] ; then
  INSTALL_CMD="nix profile install"
  INSTALL_CMD_ACTUAL="nixReplaceProfile"
  LIST_CMD="nix profile list"