In general, for unsupported (by us) Linux variants, you should install the flatpak version of ChimeraX.  In your particular case, if you don't want to use the flatpak, you might want to try the Ubuntu 24.04 version instead of the 22.04 version.  Or, if that doesn't work, copy the missing packages from an Ubuntu repository, and install them by hand before installing ChimeraX.     HTH,     Greg On 7/21/2026 6:40 AM, Bruno Hay Mele via ChimeraX-users wrote:

Hi!

I am unable to install any currently available ChimeraX release or daily build on my Debian testing because the Ubuntu packages depend on libraries that are no longer available in Debian testing.

ucsf-chimerax_1.11.1ubuntu22.04_amd64.deb ucsf-chimerax_1.12ubuntu22.04_amd64.deb ucsf-chimerax-daily:amd64=2026.07.20ubuntu22.04

fail because I do not have/cannot install  libnsl2, libosmesa6

ucsf-chimerax-daily:amd64=2026.07.20ubuntu24.04 fail because I do not have/cannot install libosmesa6

ucsf-chimerax-daily:amd64=2026.07.20ubuntu26.04 fail because I do not have/cannot install libc6 and libosmesa6

System information:

    Distribution: Debian GNU/Linux testing/forky     Architecture: amd64     Kernel: 7.0.7+deb14-amd64     glibc: 2.42-17     GPU: Intel HD Graphics 4000, using the i915 driver     Installed NIS library: libnsl3 2.0.1-2     Installed development package: libnsl-dev 2.0.1-2

    Available SONAMEs:         libnsl.so.3         libnsl.so.1         libnsl.so

    Not available from the configured Debian testing repositories:

        libnsl2         libosmesa6         libosmesa6-dev

I am somewhat puzzled because, as far as I remember, both the production and daily builds were working on this same system until roughly two weeks ago. It is possible that a recent Debian testing upgrade removed or replaced the required compatibility libraries, so I may simply have been too aggressive in keeping the system fully up to date.