Change:
I just tried updating my laptop from 16.09 to 17.03-beta and ran into the following issue when starting gnome-terminal: I have gnome-terminal installed in my user profile and exists. I believe I have managed to narrow my problem to the removal of from the DBus session configuration file, see . Adding this XML tag back to the file made gnome-terminal start up fine. As a user install and run gnome-terminal. Presumably a similar error will occur for any program relying on DBus activation. System: 17.03beta320. (Gorilla) Nix version: nix-env (Nix) 1.11.7
Sigh, DBus is tricky. I didn't know that includes XDG directories and removed it to increase purity. Sorry for that, fixed it and leaved a comment for others.
Thank you You really improved the dbus stuff and I understand the thinking behind removing standardsessionservicedirs. But yeah, unfortunately it also affected the user installed services.

Discussion:
<ins> {stdenv, fetchurl, yacc, flex, pkgconfig, glib, xz}: stdenv.mkDerivation rec { version = "0.15.2"; name = "vala-${version}"; src = fetchurl { url = "mirror://gnome/sources/vala/0.15/${name}.tar.xz"; sha256 = "0g71zq6dpqrw2f40wfzdf18fdw41ymr17laqniy2kr622hkxdi8w"; }; buildNativeInputs = [ yacc flex pkgconfig xz ]; buildInputs = [ glib ]; meta = { description = "Compiler for the GObject type system"; homepage = "http://live.gnome.org/Vala"; license = "free-copyleft"; platforms = stdenv.lib.platforms.all; maintainers = [ stdenv.lib.maintainers.antono ]; }; } </ins>

<ins> {stdenv, fetchurl, yacc, flex, pkgconfig, glib, xz}: stdenv.mkDerivation rec { version = "0.16.1"; name = "vala-${version}"; src = fetchurl { url = "mirror://gnome/sources/vala/0.16/${name}.tar.xz"; sha256 = "1n708n9ixyy9qrzyv1wf4ybvcclx43ib9ki028wwpvkz6kv8zqlb"; }; buildNativeInputs = [ yacc flex pkgconfig xz ]; buildInputs = [ glib ]; meta = { description = "Compiler for the GObject type system"; homepage = "http://live.gnome.org/Vala"; license = "free-copyleft"; platforms = stdenv.lib.platforms.all; maintainers = [ stdenv.lib.maintainers.antono ]; }; } </ins>

{stdenv, fetchurl, yacc, flex, pkgconfig, glib, xz}: stdenv.mkDerivation rec { <del> name = "vala-0.14.2"; </del> <ins> version = "0.17.2"; name = "vala-${version}"; </ins> src = fetchurl { <del> url = mirror://gnome/sources/vala/0.14/vala-0.14.2.tar.xz; sha256 = "1l5kllw9vpwv24lzv9fp64l3sad46wpxgvsgryrwlrjg91w6jzl0"; </del> <ins> url = "mirror://gnome/sources/vala/0.17/${name}.tar.xz"; sha256 = "09i2s0dwmrk147ind2dx7nq845g12fp6fsjqrphhrr0dbi0zzgh3"; </ins> }; buildNativeInputs = [ yacc flex pkgconfig xz ];

meta = { description = "Compiler for the GObject type system"; homepage = "http://live.gnome.org/Vala"; <ins> license = "free-copyleft"; platforms = stdenv.lib.platforms.all; maintainers = [ stdenv.lib.maintainers.antono ]; </ins> }; }

urweb = callPackage ../development/compilers/urweb { }; <del> vala = callPackage ../development/compilers/vala { }; </del> <ins> vala = vala17; vala15 = callPackage ../development/compilers/vala/15.2.nix { }; vala16 = callPackage ../development/compilers/vala/16.1.nix { }; vala17 = callPackage ../development/compilers/vala/default.nix { }; </ins> visualcpp = callPackage ../development/compilers/visual-c++ { };