Attrnames and package names should be as close as possible to avoid confusion.
I took care not to confuse the two mpc things during the mass-replace,
so hopefully I suceeded (tarball still builds).
Conflicts (simple):
pkgs/os-specific/linux/util-linux/default.nix
It seems this merge creates a new stdenv hash,
because we had changes on both branches :-/
- IMO using a temporary is not needed here (anymore),
- temporary at that location can cause a problem (in a specific case):
for example, when using the substituteAll function from nixpkgs
on a single file directly under /nix/store/ (or ./foo-file),
the stdenv's substitute tries to create a temporary directly under
/nix/store, which causes problems on chrooted darwin
(according to @copumpkin earlier today on IRC)
The old boot.spl.hostid option was not working correctly due to an
upstream bug.
Instead, now we will create the /etc/hostid file so that all applications
(including the ZFS kernel modules, ZFS user-space applications and other
unrelated programs) pick-up the same system-wide host id. Note that glibc
(and by extension, the `hostid` program) also respect the host id configured in
/etc/hostid, if it exists.
The hostid option is now mandatory when using ZFS because otherwise, ZFS will
require you to force-import your ZFS pools if you want to use them, which is
undesirable because it disables some of the checks that ZFS does to make sure it
is safe to import a ZFS pool.
The /etc/hostid file must also exist when booting the initrd, before the SPL
kernel module is loaded, so that ZFS picks up the hostid correctly.
The complexity in creating the /etc/hostid file is due to having to
write the host ID as a 32-bit binary value, taking into account the
endianness of the machine, while using only shell commands and/or simple
utilities (to avoid exploding the size of the initrd).
Getting the names of all environment variables is tricky. The previous
implementation easily got confused by multi-line variables. The new
one is more reliable but not still not perfect.
This works around a segfault in Bash 4.3, where the expression
"${!var}" (where var="-9") crashes under certain conditions.
http://hydra.nixos.org/build/16693445
Otherwise, stdenv won't have a reference to e.g. patchelf on Linux
(because it was passed in by mkDerivation). This causes the installer
tests to fail, because having "stdenv" in the installation CD closure
is not enough to pull in all stdenv packages.
http://hydra.nixos.org/build/16546643
