When running e.g. `nixos-option boot.kernelPackages` I get an output
like this on the current unstable channel (18.09pre144959.be1461fc0ab):
```
$ nixos-option boot.kernelPackages
Value:
*exit 1*
```
This is fairly counter-intuitive as I have no clue what might went
wrong. `strace` delivers an output like this:
```
read(3, "error: Package \342\200\230cryptodev-linu"..., 128) = 128
read(3, "ux/cryptodev/default.nix:22 is m"..., 128) = 128
read(3, "lowBroken = true; }\nin configura"..., 128) = 128
read(3, "you can add\n { allowBroken = tr"..., 128) = 128
read(3, "n)\n", 128) = 3
read(3, "", 128) = 0
```
`nixos-option` evaluates the system config using `nix-instantiate` which
might break when the evaluation fails (e.g. due to broken or unfree
packages that are prohibited to evaluate by default). The script aborts
due to the shebang `@shell@ -e`.
In order to ensure that no unexpected
behavior occurs due to removing `-e` from the interpreter the easiest
way to work around this was to wrap `nix-instantiate` in `evalNix()`
with a `set +e`. The function checks the success of the evaluation with
`$?` in the end. Additionally `evalNix` shouldn't break, if one
evaluation (e.g. the values that contain a package set by default) to
return additional information like a description.
With the change `nixos-option boot.kernelPackages` delivers the
following output for me:
```
Value:
error: Package ‘cryptodev-linux-1.9-4.14.52’ in /nix/store/47z2s8cwppymmgzw6n7pbcashikyk5jk-nixos/nixos/pkgs/os-specific/linux/cryptodev/default.nix:22 is marked as broken, refusing to evaluate.
Default:
{ __unfix__ = <LAMBDA>; acpi_call = <CODE>; amdgpu-pro = <CODE>; ati_drivers_x11 = <CODE>; batman_adv = <CODE>; bbswitch = <CODE>; bcc = <CODE>; beegfs-module = <CODE>; blcr = <CODE>; broadcom_sta = <CODE>; callPackage = <CODE>; cpupower = <CODE>; cryptodev = <CODE>; dpdk = <CODE>; e1000e = <CODE>; ena = <CODE>; evdi = <CODE>; exfat-nofuse = <CODE>; extend = <CODE>; facetimehd = <CODE>; fusionio-vsl = <CODE>; hyperv-daemons = <CODE>; ixgbevf = <CODE>; jool = <CODE>; kernel = <CODE>; lttng-modules = <CODE>; mba6x_bl = <CODE>; mwprocapture = <CODE>; mxu11x0 = <CODE>; ndiswrapper = <CODE>; netatop = <CODE>; nvidiaPackages = <CODE>; nvidia_x11 = <CODE>; nvidia_x11_beta = <CODE>; nvidia_x11_legacy304 = <CODE>; nvidia_x11_legacy340 = <CODE>; nvidiabl = <CODE>; odp-dpdk = <CODE>; openafs = <CODE>; openafs_1_8 = <CODE>; perf = <CODE>; phc-intel = <CODE>; pktgen = <CODE>; ply = <CODE>; prl-tools = <CODE>; recurseForDerivations = true; rtl8192eu = <CODE>; rtl8723bs = <CODE>; rtl8812au = <CODE>; rtl8814au = <CODE>; rtlwifi_new = <CODE>; sch_cake = <CODE>; spl = <CODE>; splLegacyCrypto = <CODE>; splStable = <CODE>; splUnstable = <CODE>; stdenv = <CODE>; sysdig = <CODE>; systemtap = <CODE>; tbs = <CODE>; tmon = <CODE>; tp_smapi = <CODE>; usbip = <CODE>; v4l2loopback = <CODE>; v86d = <CODE>; vhba = <CODE>; virtualbox = <CODE>; virtualboxGuestAdditions = <CODE>; wireguard = <CODE>; x86_energy_perf_policy = <CODE>; zfs = <CODE>; zfsLegacyCrypto = <CODE>; zfsStable = <CODE>; zfsUnstable = <CODE>; }
Example:
{ _type = "literalExample"; text = "pkgs.linuxPackages_2_6_25"; }
Description:
"This option allows you to override the Linux kernel used by\nNixOS. Since things like external kernel module packages are\ntied to the kernel you're using, it also overrides those.\nThis option is a function that takes Nixpkgs as an argument\n(as a convenience), and returns an attribute set containing at\nthe very least an attribute <varname>kernel</varname>.\nAdditional attributes may be needed depending on your\nconfiguration. For instance, if you use the NVIDIA X driver,\nthen it also needs to contain an attribute\n<varname>nvidia_x11</varname>.\n"
Declared by:
"/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/nixos/modules/system/boot/kernel.nix"
Defined by:
"/home/ma27/Projects/nixos-config/system/boot.nix"
```
This partially reverts a change from e88f28965a
which removed the `mount --rbind /sys`.
While true that the activation scripts will mount `sysfs` at `/sys`,
none of the mountpoints lower in the `/sys` tree are handled by the
activation script, which includes `efivarfs`.
This fixes #38477 since it ensures the presence of `efivarfs` in the
`/sys` tree, which is why the systemd-boot installation failed.
Because it improves out-of-the-box user experience a lot (IMHO).
(zsh completion is already on by default.)
Remove "programs.bash.enableCompletion = true" from
nixos-generate-config.pl, which feels superflous now.
Of course, you'll get a bunch of warnings from the activation script:
$ nixos-enter --root /tmp/mnt/
setting up /etc...
mount: /dev: permission denied.
mount: /dev/pts: permission denied.
mount: /dev/shm: permission denied.
mount: /sys: permission denied.
/nix/var/nix/profiles/system/activate: line 74: /proc/sys/kernel/modprobe: Permission denied
chown: changing ownership of '/run/wrappers/wrappers.0pKlU8JsvV/dbus-daemon-launch-helper': Invalid argument
NOTE: Under Linux, effective file capabilities must either be empty, or
exactly match the union of selected permitted and inheritable bits.
Failed to set capabilities on file `/run/wrappers/wrappers.0pKlU8JsvV/ping' (Operation not permitted)
chown: changing ownership of '/run/wrappers/wrappers.0pKlU8JsvV/unix_chkpwd': Invalid argument
[root@nixos:/]#
The use of Nix 2.0 significantly simplifies the installer, since we
can just pass a different store URI (--store /mnt) - it's no longer
needed to set up a chroot environment for the build, and to bootstrap
Nix into the chroot.
Also, commands that need to run in the installation (namely boot
loader installation and setting a root password) are now executed
using nixos-enter.
This also removes the need for nixos-prepare-root since any required
initialisation is done by Nix or by the activation script.
In particular, it conflicts with `services.tlp.enable` option.
There exists workaround:
```
powerManagement.cpuFreqGovernor = lib.mkForce null;
services.tlp.enable = true;
```
But should it?
Regression introduced by 801c920e95.
Since then, the btrfsSimple subtest of the installer VM test fails with:
Btrfs did not return a path for the subvolume at /
The reason for this is that the output for "btrfs subvol show" has
changed between version 4.8.2 and 4.13.1.
For example the output of "btrfs subvol show /" in version 4.8.2 was:
/ is toplevel subvolume
In version 4.13.1, the output now is the following and thus the regular
expressions used in nixos-generate-config.pl and install-grub.pl now
match (which results in the error mentioned above):
/
Name: <FS_TREE>
UUID: -
Parent UUID: -
Received UUID: -
Creation time: -
Subvolume ID: 5
Generation: 287270
Gen at creation: 0
Parent ID: 0
Top level ID: 0
Flags: -
Snapshot(s):
In order to fix this I've changed nixos-generate-config.pl and
install-grub.pl, because both use "btrfs subvol show" in a similar vein,
so the regex for parsing the output now doesn't match anymore whenever
the volume path is "/", which should result in the same behaviour as we
had with btrfs-progs version 4.8.2.
Tested against the btrfsSimple, btrfsSubvols and btrfsSubvolDefault
subtests of the installer VM test and they all succeed now.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
