[Pkg-auth-maintainers] Bug#747833: libpam-yubico: unable to dlopen: symbol ykclient_set_url_bases [...] not defined in libykclient.so.3

[Clemens Lang]

Package: libpam-yubico
Version: 2.15-1
Severity: grave
Justification: renders package unusable

Dear Maintainer,

libpam-yubico seems to be broken in its current state. PAM fails to load
the plugin with the following message in /var/log/auth.log:

  PAM unable to dlopen(pam_yubico.so): /lib/security/pam_yubico.so: symbol ykclient_set_url_bases, version YKCLIENT_2.12 not defined in file libykclient.so.3 with link time reference

The following output might be helpful in debugging the problem:

  # readelf --syms /lib/security/pam_yubico.so | grep ykclient_set_url
    20: 0000000000000000     0 FUNC    GLOBAL DEFAULT  UND ykclient_set_url_bases at YKCLIENT_2.12 (10)
    76: 0000000000000000     0 FUNC    GLOBAL DEFAULT  UND ykclient_set_url_template at Base (14)

  # readelf --syms /usr/lib/x86_64-linux-gnu/libykclient.so.3 | grep ykclient_set_url
    53: 0000000000003800    29 FUNC    GLOBAL DEFAULT   12 ykclient_set_url_template@@Base
    62: 0000000000003620   254 FUNC    GLOBAL DEFAULT   12 ykclient_set_url_bases@@YKCLIENT_2.12
    77: 00000000000037e0    22 FUNC    GLOBAL DEFAULT   12 ykclient_set_url_template@@Base

I don't know enough about symbol versioning to find out what went wrong
here, but it seems the different number of @ signs in the symbol names
are to blame. Would a rebuild fix this?

-- System Information:
Debian Release: jessie/sid
  APT prefers testing-updates
  APT policy: (500, 'testing-updates'), (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 3.13-1-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages libpam-yubico depends on:
ii  debconf [debconf-2.0]  1.5.53
ii  libc6                  2.18-5
ii  libldap-2.4-2          2.4.39-1
ii  libpam-runtime         1.1.8-3
ii  libpam0g               1.1.8-3
ii  libykclient3           2.12-1
ii  libykpers-1-1          1.15.1-1
ii  libyubikey0            1.11-2

libpam-yubico recommends no packages.

libpam-yubico suggests no packages.

-- debconf information:
  libpam-yubico/module_args: mode=client try_first_pass id=3 key=SECRETSECRETSECRETSECRETSEC= url=https://secreturl.example.net/wsapi/2.0/verify?id=%d&otp=%s