NIX_PROFILES is space separated list of directories, and passing it into
for as is is considered to be 1-element list with the whole string. With
shwordsplit option Zsh emulates other shells in this regard ans
implicitely splits unquoted strings into words.
Fixes#4167.
This removes part of the PATH that were being added automatically in multi-user installs:
- $HOME/.nix-profile/lib/kde4/libexec - shouldn't be needed anymore, we are now using kde5
- @localstatedir@/nix/profiles/default/lib/kde4/libexec - same as above
- @localstatedir@/nix/profiles/default - shouldn't ever contain binaries
If the profile is sourced inside a script with `set -u`, the check for
__ETC_PROFILE_NIX_SOURCED and NIX_SSL_CERT_FILE would raise an error.
A simple guard around this check allows the script to operate under
standard environments (where it is fairly reasonable to assume USER
and HOME are set.)
