"lxc profile edit" confused by nanorc

candlerb · January 30, 2022, 7:50pm

This is a minor issue, but still has me scratching my head.

The nano editor is working fine on my system, with no errors or warnings. However when I try to do lxc profile edit, which picks up nano by default, it has a problem:

root@nuc1:~# lxc profile edit br249
Error in /etc/nanorc on line 244: Error expanding /usr/share/nano/*.nanorc: No such file or directory

The editor does work as normal, but it leaves this error on the console, and also displays [ Mistakes in '/etc/nanorc' ] in red on the editor screen.

Line 244 of /etc/nanorc says:

include "/usr/share/nano/*.nanorc"

and the referenced files do exist:

root@nuc1:~# ls /usr/share/nano/*.nanorc | head -3
/usr/share/nano/asm.nanorc
/usr/share/nano/autoconf.nanorc
/usr/share/nano/awk.nanorc

Very strange… I wonder if it’s something to do with snap packaging?

I tried running it under strace:

strace -f lxc profile edit br249 2>strace.out
...
grep -3 nano[^s] strace.out
...
[pid 3483729] rt_sigaction(SIGTERM, NULL, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 8) = 0
[pid 3483729] rt_sigaction(SIGTERM, {sa_handler=SIG_DFL, sa_mask=~[RTMIN RT_1], sa_flags=SA_RESTORER, sa_restorer=0x7fb6a224f210}, NULL, 8) = 0
[pid 3483729] read(10, "#!/bin/sh\nrun_cmd() {\n    CMD=\"$"..., 8192) = 1654
[pid 3483729] execve("/run/bin/nano", ["nano", "/tmp/lxd_editor_3443541145.yaml"], 0x55b031867ca8 /* 52 vars */) = -1 ENOENT (No such file or directory)
[pid 3483729] execve("/snap/lxd/22292/usr/sbin/nano", ["nano", "/tmp/lxd_editor_3443541145.yaml"], 0x55b031867ca8 /* 52 vars */) = -1 ENOENT (No such file or directory)
[pid 3483729] execve("/snap/lxd/22292/usr/bin/nano", ["nano", "/tmp/lxd_editor_3443541145.yaml"], 0x55b031867ca8 /* 52 vars */) = -1 ENOENT (No such file or directory)
[pid 3483729] execve("/snap/lxd/22292/sbin/nano", ["nano", "/tmp/lxd_editor_3443541145.yaml"], 0x55b031867ca8 /* 52 vars */) = -1 ENOENT (No such file or directory)
[pid 3483729] execve("/snap/lxd/22292/bin/nano", ["nano", "/tmp/lxd_editor_3443541145.yaml"], 0x55b031867ca8 /* 52 vars */) = 0
[pid 3483729] brk(NULL)                 = 0x55dcb34cd000
[pid 3483729] arch_prctl(0x3001 /* ARCH_??? */, 0x7ffe300973e0) = -1 EINVAL (Invalid argument)
[pid 3483729] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f01efe15000
--
[pid 3483729] fstat(3, {st_mode=S_IFREG|0644, st_size=201272, ...}) = 0
[pid 3483729] mmap(NULL, 201272, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f01ef9fc000
[pid 3483729] close(3)                  = 0
[pid 3483729] access("/etc/nanorc", R_OK) = 0
[pid 3483729] stat("/etc/nanorc", {st_mode=S_IFREG|0644, st_size=10037, ...}) = 0
[pid 3483729] openat(AT_FDCWD, "/etc/nanorc", O_RDONLY) = 3
[pid 3483729] fstat(3, {st_mode=S_IFREG|0644, st_size=10037, ...}) = 0
[pid 3483729] read(3, "## Sample initialization file fo"..., 4096) = 4096
[pid 3483729] read(3, "  Status-bar messages will disap"..., 4096) = 4096
[pid 3483729] read(3, "iles as follows:\n##\n##   include"..., 4096) = 1845
[pid 3483729] openat(AT_FDCWD, "/usr/share/nano", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = -1 ENOENT (No such file or directory)
[pid 3483729] openat(AT_FDCWD, "/usr/share/locale/en_GB/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
[pid 3483729] openat(AT_FDCWD, "/usr/share/locale/en/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
[pid 3483729] openat(AT_FDCWD, "/usr/share/locale-langpack/en_GB/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
[pid 3483729] openat(AT_FDCWD, "/usr/share/locale-langpack/en/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
[pid 3483729] openat(AT_FDCWD, "/usr/share/locale/en_GB/LC_MESSAGES/nano.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
[pid 3483729] openat(AT_FDCWD, "/usr/share/locale/en/LC_MESSAGES/nano.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
[pid 3483729] openat(AT_FDCWD, "/usr/share/locale-langpack/en_GB/LC_MESSAGES/nano.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
[pid 3483729] openat(AT_FDCWD, "/usr/share/locale-langpack/en/LC_MESSAGES/nano.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
[pid 3483729] read(3, "", 4096)         = 0
[pid 3483729] close(3)                  = 0
[pid 3483729] geteuid()                 = 0
--
[pid 3483729] fstat(3, {st_mode=S_IFREG|0644, st_size=2359, ...}) = 0
[pid 3483729] read(3, "root:x:0:0:root:/root:/bin/bash\n"..., 4096) = 2359
[pid 3483729] close(3)                  = 0
[pid 3483729] access("/root/.nanorc", R_OK) = -1 ENOENT (No such file or directory)
[pid 3483729] access("/root/.config/nano/nanorc", R_OK) = -1 ENOENT (No such file or directory)
[pid 3483729] stat("/root/.nano/", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
[pid 3483729] openat(AT_FDCWD, "/root/.nano/search_history", O_RDONLY) = -1 ENOENT (No such file or directory)
[pid 3483729] ioctl(1, TCGETS, {B38400 opost isig icanon echo ...}) = 0
[pid 3483729] stat("/root/snap/lxd/22292/.terminfo", 0x55dcb34dbb40) = -1 ENOENT (No such file or directory)
[pid 3483729] stat("/etc/terminfo", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
--
[pid 3483729] openat(AT_FDCWD, "/tmp/.lxd_editor_3443541145.yaml.swp", O_WRONLY|O_CREAT|O_EXCL|O_APPEND, 0666) = 3
[pid 3483729] fcntl(3, F_GETFL)         = 0x8401 (flags O_WRONLY|O_APPEND|O_LARGEFILE)
[pid 3483729] fstat(3, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
[pid 3483729] write(3, "b0nano 4.8\0\0\0\0\0\0\0\0\0\0\0\0\0\0Q(5\0root"..., 1024) = 1024
[pid 3483729] close(3)                  = 0
[pid 3483729] getcwd("/root", 4097)     = 6
[pid 3483729] stat("/tmp/lxd_editor_3443541145.yaml", {st_mode=S_IFREG|0600, st_size=661, ...}) = 0
--
[pid 3483729] poll([{fd=0, events=POLLIN}], 1, 0) = 0 (Timeout)
[pid 3483729] poll([{fd=0, events=POLLIN}], 1, 0) = 0 (Timeout)
[pid 3483729] write(1, "\33[H", 3)      = 3
[pid 3483729] write(1, "\33(B\33[0;7m  GNU nano 4.8         "..., 138) = 138
[pid 3483729] write(1, "\33(B\33[m", 6) = 6
[pid 3483729] rt_sigaction(SIGTSTP, {sa_handler=0x55dcb306c9f0, sa_mask=~[KILL STOP RTMIN RT_1], sa_flags=SA_RESTORER, sa_restorer=0x7f01efbf3210}, NULL, 8) = 0
[pid 3483729] write(1, "\7", 1)         = 1
--
[pid 3483729] ioctl(0, TCGETS, {B38400 opost isig icanon echo ...}) = 0
[pid 3483729] ioctl(0, SNDCTL_TMR_START or TCSETS, {B38400 opost isig icanon echo ...}) = 0
[pid 3483729] ioctl(0, TCGETS, {B38400 opost isig icanon echo ...}) = 0
[pid 3483729] write(2, "Error in /etc/nanorc on line 244"..., 102Error in /etc/nanorc on line 244: Error expanding /usr/share/nano/*.nanorc: No such file or directory
) = 102
[pid 3483729] exit_group(0)             = ?
[pid 3483729] +++ exited with 0 +++

This does seem that it’s using its a custom bundled version of nano (really?!) and therefore makes me wonder whether it’s chrooted or something.

Anyway, I just thought I’d report it, I don’t know if there’s anything I can do about this spurious error.

Platform info: Ubuntu 20.04, upgraded from 18.04:

root@nuc1:~# snap list
Name    Version    Rev    Tracking       Publisher   Notes
core    16-2.54.2  12603  latest/stable  canonical✓  core
core18  20211215   2284   latest/stable  canonical✓  base
core20  20220114   1328   latest/stable  canonical✓  base
lxd     4.22       22292  latest/stable  canonical✓  -

stgraber · January 31, 2022, 2:57pm

Yeah, that’s because the snap itself includes nano, it tries to be nice and read your config but doesn’t actually have to your full system.

Do you have EDITOR set in your environment?
If you don’t, can you try setting it to EDITOR=nano to see if that causes the snap to spawn your OS version of nano.

candlerb · January 31, 2022, 4:36pm

export EDITOR=nano does indeed make the error go away. Thank you!

stgraber · January 31, 2022, 7:07pm

Excellent.

Basically, LXD attempts to call your host’s editor when EDITOR is set to some value.
When it’s not, it falls back to the built-in editors which currently means using built-in nano.

But then the snap has access to your /home, so if you have config in there, things can get confusing.