treewide: don't use single quotes with placeholder

pkgs/applications/display-managers/lightdm/default.nix

···
     ++ optional withQt5 "--enable-liblightdm-qt5";
 
   installFlags = [
-    "sysconfdir=${placeholder ''out''}/etc"
+    "sysconfdir=${placeholder "out"}/etc"
     "localstatedir=\${TMPDIR}"
   ];
 

pkgs/applications/misc/gpscorrelate/default.nix

···
   ];
 
   makeFlags = [
-    "prefix=${placeholder ''out''}"
+    "prefix=${placeholder "out"}"
     "GTK=3"
     "CC=cc"
     "CXX=c++"

pkgs/applications/misc/kjv/default.nix

···
   patches = [ add-apocrypha add-install-target ];
 
   makeFlags = [
-    "PREFIX=${placeholder ''out''}"
+    "PREFIX=${placeholder "out"}"
   ];
 
   meta = with stdenv.lib; {

pkgs/applications/misc/plank/default.nix

···
 
   # fix paths
   makeFlags = [
-    "INTROSPECTION_GIRDIR=${placeholder ''out''}/share/gir-1.0/"
-    "INTROSPECTION_TYPELIBDIR=${placeholder ''out''}/lib/girepository-1.0"
+    "INTROSPECTION_GIRDIR=${placeholder "out"}/share/gir-1.0/"
+    "INTROSPECTION_TYPELIBDIR=${placeholder "out"}/lib/girepository-1.0"
   ];
 
   # Make plank's application launcher hidden in Pantheon

pkgs/applications/misc/web-media-controller/default.nix

···
   nativeBuildInputs = [ cmake pkgconfig ];
   buildInputs = [ glib pcre json-glib ];
   cmakeFlags = [
-    "-DCHROMIUM_MANIFEST_DESTINATION=${placeholder ''out''}/etc/chromium/native-messaging-hosts"
-    "-DCHROME_MANIFEST_DESTINATION=${placeholder ''out''}/etc/opt/chrome/native-messaging-hosts"
-    "-DFIREFOX_MANIFEST_DESTINATION=${placeholder ''out''}/lib/mozilla/native-messaging-hosts"
+    "-DCHROMIUM_MANIFEST_DESTINATION=${placeholder "out"}/etc/chromium/native-messaging-hosts"
+    "-DCHROME_MANIFEST_DESTINATION=${placeholder "out"}/etc/opt/chrome/native-messaging-hosts"
+    "-DFIREFOX_MANIFEST_DESTINATION=${placeholder "out"}/lib/mozilla/native-messaging-hosts"
   ];
 
   meta = with stdenv.lib; {

pkgs/applications/networking/dropbox/cli.nix

···
   ];
 
   configureFlags = [
-    "--with-nautilus-extension-dir=${placeholder ''nautilusExtension''}/lib/nautilus/extensions-3.0"
+    "--with-nautilus-extension-dir=${placeholder "nautilusExtension"}/lib/nautilus/extensions-3.0"
   ];
 
   makeFlags = [
-    "EMBLEM_DIR=${placeholder ''nautilusExtension''}/share/nautilus-dropbox/emblems"
+    "EMBLEM_DIR=${placeholder "nautilusExtension"}/share/nautilus-dropbox/emblems"
   ];
 
   meta = {

pkgs/applications/science/electronics/fped/default.nix

···
 
   # This uses '/bin/bash', '/usr/local' and 'lex' by default
   makeFlags = [
-    "PREFIX=${placeholder ''out''}"
+    "PREFIX=${placeholder "out"}"
     "LEX=flex"
     "RGBDEF=${netpbm}/share/netpbm/misc/rgb.txt"
   ];

pkgs/applications/version-management/git-and-tools/git-crypt/default.nix

···
   '';
 
   makeFlags = [
-    "PREFIX=${placeholder ''out''}"
+    "PREFIX=${placeholder "out"}"
     "ENABLE_MAN=yes"
     "DOCBOOK_XSL=${docbook_xsl}/share/xml/docbook-xsl-nons/manpages/docbook.xsl"
   ];

pkgs/applications/version-management/git-and-tools/git-subrepo/default.nix

···
   ];
 
   makeFlags = [
-    "PREFIX=${placeholder ''out''}"
-    "INSTALL_LIB=${placeholder ''out''}/bin"
-    "INSTALL_MAN=${placeholder ''out''}/share/man/man1"
+    "PREFIX=${placeholder "out"}"
+    "INSTALL_LIB=${placeholder "out"}/bin"
+    "INSTALL_MAN=${placeholder "out"}/share/man/man1"
   ];
 
   patches = [

pkgs/desktops/deepin/dbus-factory/default.nix

···
     go-dbus-generator
   ];
 
-  makeFlags = [ "GOPATH=${placeholder ''out''}/share/go" ];
+  makeFlags = [ "GOPATH=${placeholder "out"}/share/go" ];
 
   postPatch = ''
     sed -i -e 's:/share/gocode:/share/go:' Makefile

pkgs/desktops/deepin/deepin-anything/default.nix

···
 
   makeFlags = [
     "DEB_HOST_MULTIARCH="
-    "PREFIX=${placeholder ''out''}"
+    "PREFIX=${placeholder "out"}"
   ];
 
   postPatch = ''

pkgs/desktops/deepin/deepin-desktop-schemas/default.nix

···
     # fix default background url
     sed -i -e 's,/usr/share/backgrounds/default_background.jpg,/usr/share/backgrounds/deepin/desktop.jpg,' \
       overrides/common/com.deepin.wrap.gnome.desktop.override
-      
+
     fixPath ${deepin-wallpapers} /usr/share/backgrounds \
       overrides/common/com.deepin.wrap.gnome.desktop.override
 
···
     #   /usr/share/desktop-directories
   '';
 
-  makeFlags = [ "PREFIX=${placeholder ''out''}" ];
+  makeFlags = [ "PREFIX=${placeholder "out"}" ];
 
   doCheck = true;
   checkTarget = "test";

pkgs/desktops/deepin/deepin-gettext-tools/default.nix

···
     python3Packages.python
   ];
 
-  makeFlags = [ "PREFIX=${placeholder ''out''}" ];
+  makeFlags = [ "PREFIX=${placeholder "out"}" ];
 
   postPatch = ''
     sed -e 's/sudo cp/cp/' -i src/generate_mo.py

pkgs/desktops/deepin/deepin-gtk-theme/default.nix

···
 
   propagatedUserEnvPkgs = [ gtk-engine-murrine ];
 
-  makeFlags = [ "PREFIX=${placeholder ''out''}" ];
+  makeFlags = [ "PREFIX=${placeholder "out"}" ];
 
   passthru.updateScript = deepin.updateScript { inherit ;name = "${pname}-${version}"; };
 

pkgs/desktops/deepin/deepin-icon-theme/default.nix

···
 
   buildTargets = "all hicolor-links";
   installTargets = "install-icons install-cursors";
-  installFlags = [ "PREFIX=${placeholder ''out''}" ];
+  installFlags = [ "PREFIX=${placeholder "out"}" ];
 
   postInstall = ''
     cp -a ./Sea ./usr/share/icons/hicolor "$out"/share/icons/

pkgs/desktops/deepin/deepin-sound-theme/default.nix

···
     sha256 = "1sw4nrn7q7wk1hpicm05apyc0mihaw42iqm52wb8ib8gm1qiylr9";
   };
 
-  makeFlags = [ "PREFIX=${placeholder ''out''}" ];
+  makeFlags = [ "PREFIX=${placeholder "out"}" ];
 
   passthru.updateScript = deepin.updateScript { inherit ;name = "${pname}-${version}"; };
 

pkgs/desktops/deepin/go-dbus-factory/default.nix

···
     sha256 = "06fqyad9f50gcjsjkh7929yyaprahdjhnd0dr4gl2797a7wysl3f";
   };
 
-  makeFlags = [ "PREFIX=${placeholder ''out''}" ];
+  makeFlags = [ "PREFIX=${placeholder "out"}" ];
 
   postPatch = ''
     sed -i -e 's:/share/gocode:/share/go:' Makefile

pkgs/desktops/deepin/go-dbus-generator/default.nix

···
   ];
 
   makeFlags = [
-    "PREFIX=${placeholder ''out''}"
+    "PREFIX=${placeholder "out"}"
     "GOCACHE=$(TMPDIR)/go-cache"
   ];
 

pkgs/desktops/deepin/go-gir-generator/default.nix

···
   '';
 
   makeFlags = [
-    "PREFIX=${placeholder ''out''}"
+    "PREFIX=${placeholder "out"}"
     "GOCACHE=$(TMPDIR)/go-cache"
   ];
 

pkgs/desktops/deepin/qt5dxcb-plugin/default.nix

···
   ];
 
   qmakeFlags = [
-    "INSTALL_PATH=${placeholder ''out''}/${qtbase.qtPluginPrefix}/platforms"
+    "INSTALL_PATH=${placeholder "out"}/${qtbase.qtPluginPrefix}/platforms"
   ];
 
   enableParallelBuilding = true;

pkgs/desktops/gnome-3/core/gnome-keyring/default.nix

···
   ];
 
   configureFlags = [
-    "--with-pkcs11-config=${placeholder ''out''}/etc/pkcs11/" # installation directories
-    "--with-pkcs11-modules=${placeholder ''out''}/lib/pkcs11/"
+    "--with-pkcs11-config=${placeholder "out"}/etc/pkcs11/" # installation directories
+    "--with-pkcs11-modules=${placeholder "out"}/lib/pkcs11/"
   ];
 
   postPatch = ''

pkgs/desktops/gnome-3/core/gnome-user-share/default.nix

···
   configureFlags = [
     "--with-httpd=${apacheHttpd.out}/bin/httpd"
     "--with-modules-path=${apacheHttpd.dev}/modules"
-    "--with-systemduserunitdir=${placeholder ''out''}/etc/systemd/user"
-    "--with-nautilusdir=${placeholder ''out''}/lib/nautilus/extensions-3.0"
+    "--with-systemduserunitdir=${placeholder "out"}/etc/systemd/user"
+    "--with-nautilusdir=${placeholder "out"}/lib/nautilus/extensions-3.0"
   ];
 
   nativeBuildInputs = [

pkgs/desktops/gnome-3/extensions/taskwhisperer/default.nix

···
   uuid = "[e-mail]";
 
   makeFlags = [
-    "INSTALLBASE=${placeholder ''out''}/share/gnome-shell/extensions"
+    "INSTALLBASE=${placeholder "out"}/share/gnome-shell/extensions"
   ];
 
   patches = [

pkgs/desktops/gnome-3/misc/gnome-applets/default.nix

···
   doCheck = true;
 
   configureFlags = [
-    "--with-libpanel-applet-dir=${placeholder ''out''}/share/gnome-panel/applets"
+    "--with-libpanel-applet-dir=${placeholder "out"}/share/gnome-panel/applets"
   ];
 
   passthru = {

pkgs/desktops/pantheon/apps/switchboard-plugs/a11y/default.nix

···
     switchboard
   ];
 
-  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder ''out''}/lib/switchboard";
+  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder "out"}/lib/switchboard";
 
   meta = with stdenv.lib; {
     description = "Switchboard Universal Access Plug";

pkgs/desktops/pantheon/apps/switchboard-plugs/about/default.nix

···
     ./remove-update-button.patch
   ];
 
-  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder ''out''}/lib/switchboard";
+  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder "out"}/lib/switchboard";
 
   meta = with stdenv.lib; {
     description = "Switchboard About Plug";

pkgs/desktops/pantheon/apps/switchboard-plugs/applications/default.nix

···
     switchboard
   ];
 
-  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder ''out''}/lib/switchboard";
+  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder "out"}/lib/switchboard";
 
   meta = with stdenv.lib; {
     description = "Switchboard Applications Plug";

pkgs/desktops/pantheon/apps/switchboard-plugs/bluetooth/default.nix

···
     switchboard
   ];
 
-  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder ''out''}/lib/switchboard";
+  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder "out"}/lib/switchboard";
 
   meta = with stdenv.lib; {
     description = "Switchboard Bluetooth Plug";

pkgs/desktops/pantheon/apps/switchboard-plugs/datetime/default.nix

···
     ./clock-format.patch
   ];
 
-  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder ''out''}/lib/switchboard";
+  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder "out"}/lib/switchboard";
 
   meta = with stdenv.lib; {
     description = "Switchboard Date & Time Plug";

pkgs/desktops/pantheon/apps/switchboard-plugs/display/default.nix

···
     switchboard
   ];
 
-  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder ''out''}/lib/switchboard";
+  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder "out"}/lib/switchboard";
 
   meta = with stdenv.lib; {
     description = "Switchboard Displays Plug";

pkgs/desktops/pantheon/apps/switchboard-plugs/keyboard/default.nix

···
     })
   ];
 
-  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder ''out''}/lib/switchboard";
+  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder "out"}/lib/switchboard";
 
   meta = with stdenv.lib; {
     description = "Switchboard Keyboard Plug";

pkgs/desktops/pantheon/apps/switchboard-plugs/mouse-touchpad/default.nix

···
     switchboard
   ];
 
-  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder ''out''}/lib/switchboard";
+  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder "out"}/lib/switchboard";
 
   meta = with stdenv.lib; {
     description = "Switchboard Mouse & Touchpad Plug";

pkgs/desktops/pantheon/apps/switchboard-plugs/network/default.nix

···
   ];
 
 
-  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder ''out''}/lib/switchboard";
+  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder "out"}/lib/switchboard";
 
   meta = with stdenv.lib; {
     description = "Switchboard Networking Plug";

pkgs/desktops/pantheon/apps/switchboard-plugs/notifications/default.nix

···
     switchboard
   ];
 
-  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder ''out''}/lib/switchboard";
+  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder "out"}/lib/switchboard";
 
   meta = with stdenv.lib; {
     description = "Switchboard Notifications Plug";

pkgs/desktops/pantheon/apps/switchboard-plugs/pantheon-shell/default.nix

···
   '';
 
 
-  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder ''out''}/lib/switchboard";
+  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder "out"}/lib/switchboard";
 
   meta = with stdenv.lib; {
     description = "Switchboard Desktop Plug";

pkgs/desktops/pantheon/apps/switchboard-plugs/power/default.nix

···
       --subst-var-by GSD_GSETTINGS_PATH ${elementary-settings-daemon}/share/gsettings-schemas/${elementary-settings-daemon.name}/glib-2.0/schemas
   '';
 
-  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder ''out''}/lib/switchboard";
-  PKG_CONFIG_DBUS_1_SYSTEM_BUS_SERVICES_DIR = "${placeholder ''out''}/share/dbus-1/system-services";
-  PKG_CONFIG_DBUS_1_SYSCONFDIR = "${placeholder ''out''}/etc";
-  PKG_CONFIG_POLKIT_GOBJECT_1_POLICYDIR = "${placeholder ''out''}/share/polkit-1/actions";
+  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder "out"}/lib/switchboard";
+  PKG_CONFIG_DBUS_1_SYSTEM_BUS_SERVICES_DIR = "${placeholder "out"}/share/dbus-1/system-services";
+  PKG_CONFIG_DBUS_1_SYSCONFDIR = "${placeholder "out"}/etc";
+  PKG_CONFIG_POLKIT_GOBJECT_1_POLICYDIR = "${placeholder "out"}/share/polkit-1/actions";
 
   meta = with stdenv.lib; {
     description = "Switchboard Power Plug";

pkgs/desktops/pantheon/apps/switchboard-plugs/printers/default.nix

···
     switchboard
   ];
 
-  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder ''out''}/lib/switchboard";
+  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder "out"}/lib/switchboard";
 
   meta = with stdenv.lib; {
     description = "Switchboard Printers Plug";

pkgs/desktops/pantheon/apps/switchboard-plugs/security-privacy/default.nix

···
     zeitgeist
   ];
 
-  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder ''out''}/lib/switchboard";
+  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder "out"}/lib/switchboard";
 
   patches = [
     ./hardcode-gsettings.patch

pkgs/desktops/pantheon/apps/switchboard-plugs/sharing/default.nix

···
     switchboard
   ];
 
-  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder ''out''}/lib/switchboard";
+  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder "out"}/lib/switchboard";
 
   meta = with stdenv.lib; {
     description = "Switchboard Sharing Plug";

pkgs/desktops/pantheon/apps/switchboard-plugs/sound/default.nix

···
     switchboard
   ];
 
-  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder ''out''}/lib/switchboard";
+  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder "out"}/lib/switchboard";
 
   meta = with stdenv.lib; {
     description = "Switchboard Sound Plug";

pkgs/desktops/pantheon/desktop/wingpanel-indicators/applications-menu/default.nix

···
    ];
 
   mesonFlags = [
-    "--sysconfdir=${placeholder ''out''}/etc"
+    "--sysconfdir=${placeholder "out"}/etc"
   ];
 
-  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder ''out''}/lib/wingpanel";
-  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder ''out''}/lib/switchboard";
+  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder "out"}/lib/wingpanel";
+  PKG_CONFIG_SWITCHBOARD_2_0_PLUGSDIR = "${placeholder "out"}/lib/switchboard";
 
   patches = [
     (substituteAll {

pkgs/desktops/pantheon/desktop/wingpanel-indicators/bluetooth/default.nix

···
     wingpanel
   ];
 
-  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder ''out''}/lib/wingpanel";
+  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder "out"}/lib/wingpanel";
 
   postPatch = ''
     chmod +x meson/post_install.py

pkgs/desktops/pantheon/desktop/wingpanel-indicators/datetime/default.nix

···
     })
   ];
 
-  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder ''out''}/lib/wingpanel";
+  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder "out"}/lib/wingpanel";
 
   postPatch = ''
     chmod +x meson/post_install.py

pkgs/desktops/pantheon/desktop/wingpanel-indicators/keyboard/default.nix

···
     })
   ];
 
-  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder ''out''}/lib/wingpanel";
+  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder "out"}/lib/wingpanel";
 
   meta = with stdenv.lib; {
     description = "Keyboard Indicator for Wingpanel";

pkgs/desktops/pantheon/desktop/wingpanel-indicators/network/default.nix

···
     wingpanel
   ];
 
-  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder ''out''}/lib/wingpanel";
+  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder "out"}/lib/wingpanel";
 
   meta = with stdenv.lib; {
     description = "Network Indicator for Wingpanel";

pkgs/desktops/pantheon/desktop/wingpanel-indicators/nightlight/default.nix

···
     wingpanel
   ];
 
-  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder ''out''}/lib/wingpanel";
+  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder "out"}/lib/wingpanel";
 
   meta = with stdenv.lib; {
     description = "Night Light Indicator for Wingpanel";

pkgs/desktops/pantheon/desktop/wingpanel-indicators/notifications/default.nix

···
     wingpanel
   ];
 
-  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder ''out''}/lib/wingpanel";
+  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder "out"}/lib/wingpanel";
 
   meta = with stdenv.lib; {
     description = "Notifications Indicator for Wingpanel";

pkgs/desktops/pantheon/desktop/wingpanel-indicators/power/default.nix

···
     wingpanel
   ];
 
-  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder ''out''}/lib/wingpanel";
+  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder "out"}/lib/wingpanel";
 
   postPatch = ''
     chmod +x meson/post_install.py

pkgs/desktops/pantheon/desktop/wingpanel-indicators/session/default.nix

···
     wingpanel
   ];
 
-  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder ''out''}/lib/wingpanel";
+  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder "out"}/lib/wingpanel";
 
   meta = with stdenv.lib; {
     description = "Session Indicator for Wingpanel";

pkgs/desktops/pantheon/desktop/wingpanel-indicators/sound/default.nix

···
     wingpanel
   ];
 
-  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder ''out''}/lib/wingpanel";
+  PKG_CONFIG_WINGPANEL_2_0_INDICATORSDIR = "${placeholder "out"}/lib/wingpanel";
 
   postPatch = ''
     chmod +x meson/post_install.py

pkgs/desktops/pantheon/services/contractor/default.nix

···
     libgee
   ];
 
-  PKG_CONFIG_DBUS_1_SESSION_BUS_SERVICES_DIR = "${placeholder ''out''}/share/dbus-1/services";
+  PKG_CONFIG_DBUS_1_SESSION_BUS_SERVICES_DIR = "${placeholder "out"}/share/dbus-1/services";
 
   meta = with stdenv.lib; {
     description = "A desktop-wide extension service used by elementary OS";

pkgs/desktops/surf-display/default.nix

···
        --prefix PATH ':' ${stdenv.lib.makeBinPath buildInputs}
   '';
 
-  makeFlags = [ "PREFIX=${placeholder ''out''}" ];
+  makeFlags = [ "PREFIX=${placeholder "out"}" ];
 
   meta = with stdenv.lib; {
     description = "Kiosk browser session manager based on the surf browser";

pkgs/desktops/xfce4-14/xfce4-session/default.nix

···
 
   buildInputs = [ exo gtk3 glib libxfce4ui libxfce4util libwnck3 xfconf polkit iceauth ];
 
-  configureFlags = [ "--with-xsession-prefix=${placeholder ''out''}" ];
+  configureFlags = [ "--with-xsession-prefix=${placeholder "out"}" ];
 
   # See https://github.com/NixOS/nixpkgs/issues/36468
   NIX_CFLAGS_COMPILE = "-I${glib.dev}/include/gio-unix-2.0";

pkgs/development/libraries/accountsservice/default.nix

···
   mesonFlags = [
     "-Dadmin_group=wheel"
     "-Dlocalstatedir=/var"
-    "-Dsystemdsystemunitdir=${placeholder ''out''}/etc/systemd/system"
+    "-Dsystemdsystemunitdir=${placeholder "out"}/etc/systemd/system"
   ];
 
   postPatch = ''

pkgs/development/libraries/bamf/default.nix

···
 
   # fix paths
   makeFlags = [
-    "INTROSPECTION_GIRDIR=${placeholder ''dev''}/share/gir-1.0/"
-    "INTROSPECTION_TYPELIBDIR=${placeholder ''out''}/lib/girepository-1.0"
+    "INTROSPECTION_GIRDIR=${placeholder "dev"}/share/gir-1.0/"
+    "INTROSPECTION_TYPELIBDIR=${placeholder "out"}/lib/girepository-1.0"
   ];
 
   preConfigure = ''

pkgs/development/libraries/dee/default.nix

···
 
   configureFlags = [
     "--disable-gtk-doc"
-    "--with-pygi-overrides-dir=${placeholder ''py''}/${python3.sitePackages}/gi/overrides"
+    "--with-pygi-overrides-dir=${placeholder "py"}/${python3.sitePackages}/gi/overrides"
   ];
 
   meta = with stdenv.lib; {

pkgs/development/libraries/gnome-menus/default.nix

···
   };
 
   makeFlags = [
-    "INTROSPECTION_GIRDIR=${placeholder ''out''}/share/gir-1.0/"
-    "INTROSPECTION_TYPELIBDIR=${placeholder ''out''}/lib/girepository-1.0"
+    "INTROSPECTION_GIRDIR=${placeholder "out"}/share/gir-1.0/"
+    "INTROSPECTION_TYPELIBDIR=${placeholder "out"}/lib/girepository-1.0"
   ];
 
   nativeBuildInputs = [ pkgconfig gettext ];

pkgs/development/libraries/graphene/default.nix

···
 
   mesonFlags = [
     "-Dgtk_doc=true"
-    "-Dinstalled_test_datadir=${placeholder ''installedTests''}/share"
-    "-Dinstalled_test_bindir=${placeholder ''installedTests''}/libexec"
+    "-Dinstalled_test_datadir=${placeholder "installedTests"}/share"
+    "-Dinstalled_test_bindir=${placeholder "installedTests"}/libexec"
   ];
 
   nativeBuildInputs = [

pkgs/development/libraries/libaccounts-glib/default.nix

···
   # See: https://gitlab.com/accounts-sso/libaccounts-glib/merge_requests/22
   patches = [ ./py-override.patch ];
 
-  nativeBuildInputs = [ 
+  nativeBuildInputs = [
     check
     docbook_xml_dtd_43
     docbook_xsl
···
   LC_ALL = "en_US.UTF-8";
 
   mesonFlags = [
-    "-Dpy-overrides-dir=${placeholder ''py''}/${python3.sitePackages}/gi/overrides"
+    "-Dpy-overrides-dir=${placeholder "py"}/${python3.sitePackages}/gi/overrides"
   ];
 
   meta = with stdenv.lib; {

pkgs/development/libraries/libdbusmenu/default.nix

···
   doCheck = false; # generates shebangs in check phase, too lazy to fix
 
   installFlags = [
-    "sysconfdir=${placeholder ''out''}/etc"
+    "sysconfdir=${placeholder "out"}/etc"
     "localstatedir=\${TMPDIR}"
-    "typelibdir=${placeholder ''out''}/lib/girepository-1.0"
+    "typelibdir=${placeholder "out"}/lib/girepository-1.0"
   ];
 
   meta = {

pkgs/development/libraries/libgdata/default.nix

···
 
   mesonFlags = [
     "-Dgtk_doc=false"
-    "-Dinstalled_test_bindir=${placeholder ''installedTests''}/libexec"
-    "-Dinstalled_test_datadir=${placeholder ''installedTests''}/share"
+    "-Dinstalled_test_bindir=${placeholder "installedTests"}/libexec"
+    "-Dinstalled_test_datadir=${placeholder "installedTests"}/share"
     "-Dinstalled_tests=true"
   ];
 

pkgs/development/libraries/libgpiod/default.nix

···
   configureFlags = [
     "--enable-tools=${if enable-tools then "yes" else "no"}"
     "--enable-bindings-cxx"
-    "--prefix=${placeholder ''out''}"
+    "--prefix=${placeholder "out"}"
   ];
 
   meta = with stdenv.lib; {

pkgs/development/libraries/libirecovery/default.nix

···
   # as only the `idevicerestore` binary was tested so far (which worked
   # without further configuration).
   configureFlags = [
-    "--with-udevrulesdir=${placeholder ''out''}/lib/udev/rules.d"
+    "--with-udevrulesdir=${placeholder "out"}/lib/udev/rules.d"
     ''--with-udevrule="OWNER=\"root\", GROUP=\"myusergroup\", MODE=\"0660\""''
   ];
 

pkgs/development/libraries/libmbim/default.nix

···
   outputs = [ "out" "dev" "man" ];
 
   configureFlags = [
-    "--with-udev-base-dir=${placeholder ''out''}/lib/udev"
+    "--with-udev-base-dir=${placeholder "out"}/lib/udev"
   ];
 
   nativeBuildInputs = [

pkgs/development/libraries/libqmi/default.nix

···
   outputs = [ "out" "dev" "devdoc" ];
 
   configureFlags = [
-    "--with-udev-base-dir=${placeholder ''out''}/lib/udev"
+    "--with-udev-base-dir=${placeholder "out"}/lib/udev"
   ];
 
   nativeBuildInputs = [

pkgs/development/libraries/libunity/default.nix

···
 
   configureFlags = [
     "--disable-static"
-    "--with-pygi-overrides-dir=${placeholder ''py''}/${python3.sitePackages}/gi/overrides"
+    "--with-pygi-overrides-dir=${placeholder "py"}/${python3.sitePackages}/gi/overrides"
   ];
 
   meta = with stdenv.lib; {

pkgs/development/libraries/tracker/default.nix

···
   LC_ALL = "en_US.UTF-8";
 
   mesonFlags = [
-    "-Ddbus_services=${placeholder ''out''}/share/dbus-1/services"
-    "-Dsystemd_user_services=${placeholder ''out''}/lib/systemd/user"
+    "-Ddbus_services=${placeholder "out"}/share/dbus-1/services"
+    "-Dsystemd_user_services=${placeholder "out"}/lib/systemd/user"
     # TODO: figure out wrapping unit tests, some of them fail on missing gsettings-desktop-schemas
     "-Dfunctional_tests=false"
     "-Ddocs=true"

pkgs/development/libraries/zeitgeist/default.nix

···
 
   preConfigure = "NOCONFIGURE=1 ./autogen.sh";
 
-  configureFlags = [ "--with-session-bus-services-dir=${placeholder ''out''}/share/dbus-1/services" ];
+  configureFlags = [ "--with-session-bus-services-dir=${placeholder "out"}/share/dbus-1/services" ];
 
   nativeBuildInputs = [
     autoconf automake libtool pkgconfig gettext gobject-introspection vala python2Packages.python

pkgs/os-specific/linux/upower/default.nix

···
     "--localstatedir=/var"
   ]
   ++ stdenv.lib.optional useSystemd [
-    "--with-systemdsystemunitdir=${placeholder ''out''}/etc/systemd/system"
-    "--with-systemdutildir=${placeholder ''out''}/lib/systemd"
-    "--with-udevrulesdir=${placeholder ''out''}/lib/udev/rules.d"
+    "--with-systemdsystemunitdir=${placeholder "out"}/etc/systemd/system"
+    "--with-systemdutildir=${placeholder "out"}/lib/systemd"
+    "--with-udevrulesdir=${placeholder "out"}/lib/udev/rules.d"
   ]
   ;
 

pkgs/tools/audio/mp3cat/default.nix

···
   };
 
   makeFlags = [
-    "PREFIX=${placeholder ''out''}"
+    "PREFIX=${placeholder "out"}"
   ];
 
   installTargets = [

pkgs/tools/misc/most/default.nix

···
   outputs = [ "out" "doc" ];
 
   makeFlags = [
-    "DOC_DIR=${placeholder ''doc''}/share/doc/most"
+    "DOC_DIR=${placeholder "doc"}/share/doc/most"
   ];
 
   preConfigure = ''

pkgs/tools/networking/modem-manager/default.nix

···
 
   configureFlags = [
     "--with-polkit"
-    "--with-udev-base-dir=${placeholder ''out''}/lib/udev"
-    "--with-dbus-sys-dir=${placeholder ''out''}/etc/dbus-1/system.d"
-    "--with-systemdsystemunitdir=${placeholder ''out''}/etc/systemd/system"
+    "--with-udev-base-dir=${placeholder "out"}/lib/udev"
+    "--with-dbus-sys-dir=${placeholder "out"}/etc/dbus-1/system.d"
+    "--with-systemdsystemunitdir=${placeholder "out"}/etc/systemd/system"
     "--sysconfdir=/etc"
     "--localstatedir=/var"
     "--with-systemd-suspend-resume"

pkgs/tools/networking/ofono/default.nix

···
   ];
 
   configureFlags = [
-    "--with-dbusconfdir=${placeholder ''out''}/share"
-    "--with-systemdunitdir=${placeholder ''out''}/lib/systemd/system"
+    "--with-dbusconfdir=${placeholder "out"}/share"
+    "--with-systemdunitdir=${placeholder "out"}/lib/systemd/system"
     "--enable-external-ell"
   ];
 

pkgs/tools/security/sequoia/default.nix

···
   ;
 
   makeFlags = [
-    "PREFIX=${placeholder ''out''}"
+    "PREFIX=${placeholder "out"}"
   ];
 
   buildFlags = [