pam-u2f and glibc issues

[Fredrik Salomonsson <plattfot@posteo.net>]

Hi,

Encountered a strange issue when I did a system update this weekend.
My u2f login stopped working for swaylock.  I checked the
/var/log/secure and found:

```
Sep  9 20:17:38 localhost swaylock: PAM unable to dlopen(/gnu/store/hnih46irf9zjwn8fvqka2wryb2m4y71g-pam-u2f-1.0.8/lib/security/pam_u2f.so): /gnu/store/ln6hxqjvz6m9gdd9s97pivlqck7hzs99-glibc-2.35/lib/libc.so.6: version `GLIBC_2.38' not found (required by /gnu/store/hnih46irf9zjwn8fvqka2wryb2m4y71g-pam-u2f-1.0.8/lib/security/pam_u2f.so)
Sep  9 20:17:38 localhost swaylock: PAM adding faulty module: /gnu/store/hnih46irf9zjwn8fvqka2wryb2m4y71g-pam-u2f-1.0.8/lib/security/pam_u2f.so
Sep  9 20:17:38 localhost swaylock: PAM unable to dlopen(/gnu/store/xcmvyjzf69xfpbpahncskblyybg5b5cp-elogind-252.9/lib/security/pam_elogind.so): /gnu/store/ln6hxqjvz6m9gdd9s97pivlqck7hzs99-glibc-2.35/lib/libm.so.6: version `GLIBC_2.39' not found (required by /gnu/store/xcmvyjzf69xfpbpahncskblyybg5b5cp-elogind-252.9/lib/security/pam_elogind.so)
Sep  9 20:17:38 localhost swaylock: PAM adding faulty module: /gnu/store/xcmvyjzf69xfpbpahncskblyybg5b5cp-elogind-252.9/lib/security/pam_elogind.so
```

Looks like something is still running glibc@2.35 (linux-pam?) and trying
to load pam_u2f which is built with glibc@2.39 (and also pam_elogind
with the same result).  I'm not sure how to track down what is still
using glibc@2.35.  I checked with `guix refresh -T` for both pam-u2f and
linux-pam and both report depending on 2.39.

Here is what `guix describe` reports:

```
Generation 114	sep 08 2024 20:17:45	(current)
  plt 69ca530
    repository URL: https://git.sr.ht/~plattfot/plt
    branch: master
    commit: 69ca530fc3f00077898b6d55ecd623d5c2adc590
  guix 056910e
    repository URL: https://git.savannah.gnu.org/git/guix.git
    branch: master
    commit: 056910ec864cb7cf3225a0c27679d94405db7dcd
  nonguix e6b3bb8
    repository URL: https://gitlab.com/nonguix/nonguix
    branch: master
    commit: e6b3bb87a46024cd6b2fb1a1cad1387de0053f44
```

And I reconfigured my system using:

```
sudo guix system reconfigure -e '(@ (plt system machines heimdal) plt-heimdal-os)'
```

I.e. using this config[0].  

I tested using the linux-libre kernel, the defaults for the firmware etc
and encountered the same issue.  So I don't think it's coming from any
of the other channels.  Anyone have any idea how I can track this down?

Thanks

[0] https://git.sr.ht/~plattfot/plt/tree/69ca530fc3f00077898b6d55ecd623d5c2adc590/item/plt/system/machines/heimdal.scm

-- 
s/Fred[re]+i[ck]+/Fredrik/g