demm
The rebuild you metion did not work. Same issue.
I will figure out how to do the downgrade.
Hope the new rebuild comes soon.

    I will need help debugging this, since I'm not a latex/texlive user.
    If the issue is with /usr/bin/latex, then it is texlive-bin. See if this works (meaning that version is in your cache):

    sudo pacman -U /var/cache/pacman/pkg/texlive-bin-2018.47465-10-x86_64.pkg.tar.xz

      demm
      Sorry demm, I said I have a vanilla installation of KaOS 2020.01, so no way I can find the 2018's packages in my cache.
      I will try to look in an old machine with KaOS (not with me at the moment). Perhaps are still there.
      Any other way to get them? Or should I better wait until the new build.
      Sorry not being so helpful in the debugging.

        I've uploaded the file:

        sudo pacman -U https://sourceforge.net/projects/kaosx/files/packages/texlive-bin-2018.47465-10-x86_64.pkg.tar.xz

        Hi demm, It did not work.
        I tried your new package update as well and no luck.
        I was reading forums of other distros (with old issues also pointing to the "cannot open log file" thing in kile), some are misleading, but some say, that as the output is:
        I can't find the format file pdflatex.fmt!
        Means that some files or their symlinks are missing or misplaced. Probably after the last upgrade.
        They suggest create new symlinks for the .fmt packages and place them where Kile can see them. Though no idea in KaOS where these are located and/or how to do this.
        I will try to keep looking at this.

        Hope we can find a fix soon.

        As you say demm, It seems that the problem is directly in texlive not in kile.
        In my last attempt, I uninstall everything and tried to compile a LaTeX file (pdflatex) directly in terminal with a fresh texlive installation (without Kile).

        $ pdflatex file.tex 

This is pdfTeX, Version 3.14159265-2.6-1.40.20 (TeX Live 2019/KaOS) (preloaded format=pdflatex)
 restricted \write18 enabled.

kpathsea: Running mktexfmt pdflatex.fmt
mktexfmt: mktexfmt is using the following fmtutil.cnf files (in precedence order):
mktexfmt:   /etc/texmf/web2c/fmtutil.cnf
mktexfmt: mktexfmt is using the following fmtutil.cnf file for writing changes:
mktexfmt:   /home/username/.texlive/texmf-config/web2c/fmtutil.cnf
mktexfmt [INFO]: writing formats under /home/username/.texlive/texmf-var/web2c
mktexfmt [INFO]: did not find entry for byfmt=pdflatex, skipped
mktexfmt [INFO]: Total formats: 0
mktexfmt [INFO]: exiting with status 0
I can't find the format file `pdflatex.fmt'!

        Same happens if i try to compile the file.tex to DVI using latex instead of PDFLatex.
        Please see my previous post, it seems that the paths for texlive to find the latex format files are misleading.

        demm
        Well, the scripts run without issues, but No, they did not work to fix the problem.

          5 days later

          Do you have ffcall installed, if not, can you try if adding it helps? It is a makedepends now, but seems should be made a depend.

          I installed it and reinstalled tex-live (bin, core, latexextras) and kile, and still the same issue

          16 days later

          This morning I've freshly re-installed Kaos, including all tex and latex packages from the main app list.
          When compiling a test.tex doc, there were problems with latex and pdflatex (wrong /etc/texmf/web2c/fmtutil.cnf file or missing config file?).

          `$ pdflatex test.tex
          This is pdfTeX, Version 3.14159265-2.6-1.40.20 (TeX Live 2019/KaOS) (preloaded format=pdflatex)
          restricted \write18 enabled.

          kpathsea: Running mktexfmt pdflatex.fmt
          mktexfmt: mktexfmt is using the following fmtutil.cnf files (in precedence order):
          mktexfmt: /etc/texmf/web2c/fmtutil.cnf
          mktexfmt: mktexfmt is using the following fmtutil.cnf file for writing changes:
          mktexfmt: /home/tom/.texlive/texmf-config/web2c/fmtutil.cnf
          mktexfmt [INFO]: writing formats under /home/tom/.texlive/texmf-var/web2c
          mktexfmt [INFO]: did not find entry for byfmt=pdflatex, skipped
          mktexfmt [INFO]: Total formats: 0
          mktexfmt [INFO]: exiting with status 0
          I can't find the format file pdflatex.fmt'!
          `latex test.tex
          This is pdfTeX, Version 3.14159265-2.6-1.40.20 (TeX Live 2019/KaOS) (preloaded format=latex)
          restricted \write18 enabled.

          kpathsea: Running mktexfmt latex.fmt
          mktexfmt: mktexfmt is using the following fmtutil.cnf files (in precedence order):
          mktexfmt: /etc/texmf/web2c/fmtutil.cnf
          mktexfmt: mktexfmt is using the following fmtutil.cnf file for writing changes:
          mktexfmt: /home/tom/.texlive/texmf-config/web2c/fmtutil.cnf
          mktexfmt [INFO]: writing formats under /home/tom/.texlive/texmf-var/web2c
          mktexfmt [INFO]: did not find entry for byfmt=latex, skipped
          mktexfmt [INFO]: Total formats: 0
          mktexfmt [INFO]: exiting with status 0
          I can't find the format file latex.fmt'!

          • demm replied to this.
            Merged 1 post from latex/pdftex unable to make .fmt files.

            thomaslemmens merged it with existing texlive thread, so far no known fix for this bug.
            All I can do is upload all texlive packages from 2018, see if it is an issue with the 2019 versions only.

            sudo pacman -U https://sourceforge.net/projects/kaosx/files/packages/texlive-bin-2018.47465-10-x86_64.pkg.tar.xz https://sourceforge.net/projects/kaosx/files/packages/texlive-core-2018.47471-2-x86_64.pkg.tar.xz

              man fmutil says:

              Otherwise, fmtutil
              reads all the fmtutil.cnf files found by running `kpsewhich -all fmtutil.cnf', in the order returned by kpsewhich.<

              So, in the shell:

              kpsewhich -all fmtutil.cnf
              /etc/texmf/web2c/fmtutil.cnf
              ``
              The returned config file has only outcommented lines.

              Hope this helps in solving the issue.

              Please try only texlive-core first, looks like the issue should be there.

              After downgrading to the 2018 version pdflatex compiled as expected without errors.

              In the terminal:

              kpsewhich -all fmtutil.cnf
              /etc/texmf/web2c/fmtutil.cnf
              /usr/share/texmf-dist/web2c/fmtutil.cnf

              The first returned config file looked identical as in the 2019-version (only outcommented lines).
              The second is missing in the 2019-version and is the actual config file fmtutil needs in making texformats

              • demm replied to this.

                After backing up the second config file, I upgraded to the actual version which returned a broken system again. After copying the backed up config file to /etc/texmf/web2c (/usr/share/techmf-dist/web2c/fmtutil.cnf was not returned by kpsewhich -all fmtutil.cnf and the replaced config file in /etc/texmf/web2c only had outcommented lines) and after deleting the .texlive map in /home/user, the 2019 tex system worked as expected (without errors). The /home/user/.texlive map had to be deleted since there existed format files constructed by fmtutil from the 2018 version (>resulted in errors).

                Maybe a somewhat 'cleaner' repair is to copy the backed up file to /usr/share/techmf-dist/web2c/ . But since kpathsea cannot find this newly inserted (was missing) config file, you have to complete the ls-R database. The command mktexlsr (as root!) is used to generate the ls-R databases used by the kpathsea library. It will create them for the specified directories, or for a default list if no directories are specified.

                So it is my understanding that it is just texlive-core.

                3 months later

                The downgrade of texlive-core and bin to 2018 version worked for a while. However since an update a bit more than 1 month ago (before the Covid-19 lock-down), this downgrade stopped working. Now either the new 2019 nor the 2018 version work. Is there an actual solution for this problem that you can point me at? My work depends on this and I am tired of using another distro in another machine to generate my document files. Thanks in advance.