A Change in the TinyTeX Installation Path on Windows

Since about a month ago, I have been receiving error reports from TinyTeX users saying “TinyTeX\bin\windows\runscript.tlu:864: no appropriate script or program found: fmtutil” or “I can't find the format file `pdflatex.fmt'!”, which I do not understand.

For the last few days, I scratched my head, banged against the wall, did some research, asked R and LaTeX experts in mailing lists, got reminded of “[[alternative HTML version deleted]]” again (and apologized, of course), dug out an old Windows laptop, proudly created a new user account with my authentic Chinese name for the first time of my life (instead of using Pinyin), went through trial and error, learned a variety of bizarreness of Windows batch scripts as well as the Stack Overflow cures, summoned all Chinese students in my alma mater to test their own Windows machines and the Windows servers in their department, and meditated on the meaning of life for three seconds. Finally I’m happy to announce that I have found a fix and applied it to tinytex (the R package) v0.49.

TLDR; The fix

If you have run into the above errors when rendering R Markdown or Quarto or LaTeX documents to PDF, you can install the latest version of tinytex from CRAN:

install.packages('tinytex')

Please remember to restart R after installation. Then make sure packageVersion('tinytex') >= '0.49').

The problem

If your Windows username does not contain spaces or non-ASCII characters, this problem should not affect you.

Sys.getenv('APPDATA')
xfun::is_ascii(.Last.value) && !grepl(' ', .Last.value)

Although I have used LaTeX for nearly two decades, I have learned for the first time (from Akira Kakuto) that TeX Live does not work on Windows when its installation path contains non-ASCII characters. By default, TinyTeX is installed to the path defined by the environment variable APPDATA, which is of the form C:\Users\username\AppData\Roaming. The problem comes from the username in this path, which can contain multibyte characters, and cause TeX Live to fail with a lot of error messages like below:

! warning: kpathsea: configuration file texmf.cnf not found in these directories: 
....
! ...s\username\AppData\Roaming\TinyTeX\bin\windows\runscript.tlu:941: ...s\username\AppData\Roaming\TinyTeX\bin\windows\runscript.tlu:864: no appropriate script or program found: fmtutil
! Running the command C:\Users\username\AppData\Roaming\TinyTeX\bin\windows\fmtutil-user.exe

! kpathsea: Running mktexfmt pdflatex.fmt

! The command name is C:\Users\username\AppData\Roaming\TinyTeX\bin\windows\mktexfmt

In theory, username containing spaces should be fine, because a space is an ASCII character. However, I have received reports that spaces can be trouble, too. I do know why (is this recent bug fix in base R relevant?).

The change

With tinytex v0.49, when your APPDATA path contains spaces or non-ASCII characters:

• If you run tinytex::install_tinytex() to install TinyTeX for the first time on a computer, it will install TinyTeX to the path defined by the environment variable ProgramData, which is typically C:\ProgramData. This path has no spaces or non-ASCII characters, but note that it is hidden by default (which is harmless). In addition, this folder is shared by all users in the system. If you have multiple users, this could be a problem. For example, other users can change or override your installation. If this is a concern, you can specify a different path via the dir argument of install_tinytex(). Remember this path should not contain special characters, either.

• If TinyTeX has already been installed to APPDATA, you will get a warning message telling you how to move it to ProgramData (you can also move it to another place if you want—just specify a different path to the to argument below). You may have to restart R or even the system after moving TinyTeX.

tinytex::copy_tinytex(to = Sys.getenv('ProgramData'), move = TRUE)

The installation script install-bin-windows.bat has also been updated accordingly.

A potential flaw

The above fix is based on the assumption that ProgramData is writable, which appears to be true according to various tests that I asked for from some students. If it is not true, you will have to specify your own installation path in tinytex::install_tinytex(), or if you use the Windows batch file, you can set the environment variable TINYTEX_DIR (which defaults to APPDATA or ProgramData).

Quarto users

The command quarto install tinytex is also impacted by this problem on Windows, and I have submitted a similar fix to Quarto. Before it is applied, moving TinyTeX by yourself can also fix the problem. The only issue is that for non-R users, there is not an automatic solution like calling an R function, and you will have to move it manually (then run tlmgr path add and also tlmgr postaction install script xetex if you use XeLaTeX).

If any Windows users run into any issues when installing or moving TinyTeX to the ProgramData folder, please feel free to let me know. Thanks!