Windows ERROR: Problem running `fmtutil-sys --all` to rebuild format tree.

[reckoner]

I have:

• searched the issue tracker for similar issues
• installed the latest version of Quarto CLI
• formatted my issue following the Bug Reports guide

Bug description

tries to update latex packages and fails

Steps to reproduce

quarto render --to pdf

Actual behavior

Rendering PDF
running xelatex - 1
This is XeTeX, Version 3.141592653-2.6-0.999998 (TeX Live 2026) (preloaded format=xelatex)
restricted \write18 enabled.
entering extended mode

updating tlmgr

updating existing packages
finding package for tikzlibrarytopaths.code.tex

1 package to install
installing pgf (1 of 1)
WARN: Error encountered when rendering files
ERROR: Problem running fmtutil-sys --all to rebuild format tree.

Stack trace:
at renderFiles (file:///D:/quarto_book/.venv/Lib/site-packages/quarto_cli/bin/quarto.js:136608:49)
at eventLoopTick (ext:core/01_core.js:179:7)
at async renderProject (file:///D:/quarto_book/.venv/Lib/site-packages/quarto_cli/bin/quarto.js:137151:23)
at async _Command.actionHandler (file:///D:/quarto_book/.venv/Lib/site-packages/quarto_cli/bin/quarto.js:142481:24)
at async _Command.execute (file:///D:/quarto_book/.venv/Lib/site-packages/quarto_cli/bin/quarto.js:102102:7)
at async _Command.parseCommand (file:///D:/quarto_book/.venv/Lib/site-packages/quarto_cli/bin/quarto.js:101979:14)
at async quarto4 (file:///D:/quarto_book/.venv/Lib/site-packages/quarto_cli/bin/quarto.js:187653:5)
at async file:///D:/quarto_book/.venv/Lib/site-packages/quarto_cli/bin/quarto.js:187681:5
at async file:///D:/quarto_book/.venv/Lib/site-packages/quarto_cli/bin/quarto.js:187536:14
at async mainRunner (file:///D:/quarto_book/.venv/Lib/site-packages/quarto_cli/bin/quarto.js:187538:5)

Expected behavior

should create pdf (it used to work!)

Your environment

windows 10/11

Quarto check output

Quarto 1.9.37
[>] Checking environment information...
Quarto cache location: C:\Users\reckoner\AppData\Local\quarto
[>] Checking versions of quarto binary dependencies...
Pandoc version 3.8.3: OK
Dart Sass version 1.87.0: OK
Deno version 2.4.5: OK
Typst version 0.14.2: OK
[>] Checking versions of quarto dependencies......OK
[>] Checking Quarto installation......OK
Version: 1.9.37
Path: D:\quarto_book.venv\Lib\site-packages\quarto_cli\bin
CodePage: 1252

[>] Checking tools....................OK
TinyTeX: v2026.04
Chromium: (not installed)
Chrome Headless Shell: (not installed)
VeraPDF: (not installed)

[>] Checking LaTeX....................OK
Using: TinyTex
Path: C:\Users\reckoner\AppData\Roaming\TinyTeX\bin\windows
Version: 2026

[>] Checking Chrome Headless....................OK
Using: Chrome found on system
Path: C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
Source: Windows Registry

[>] Checking basic markdown render....OK

[>] Checking R installation...........(None)

  Unable to locate an installed version of R.
  Install R from https://cloud.r-project.org/

[>] Checking Python 3 installation....(None)

  Unable to locate an installed version of Python 3.
  Install Python 3 from https://www.python.org/downloads/

[>] Checking Julia installation...

[reckoner]

I cannot render my pdf anymore. I'm using TinyTex which is the latest version. I read

https://github.com/quarto-dev/quarto-cli/pull/10209/commits

and reinstalled per those suggestions. I went directly to the tinytex bin directory and ran all the update commands but
it still keeps wanting to update tlmgr even though I updated manually from the tinytex directory.

I'm stuck. :(

Rendering PDF
running xelatex - 1
  This is XeTeX, Version 3.141592653-2.6-0.999998 (TeX Live 2026) (preloaded format=xelatex)
   restricted \write18 enabled.
  entering extended mode

updating tlmgr

updating existing packages
finding package for tikzlibrarytopaths.code.tex
> 1 package to install
> installing pgf (1 of 1)
WARN: Error encountered when rendering files
ERROR: Problem running `fmtutil-sys --all` to rebuild format tree.

Stack trace:
    at renderFiles (file:///D:/quarto_book/.venv/Lib/site-packages/quarto_cli/bin/quarto.js:136608:49)
    at eventLoopTick (ext:core/01_core.js:179:7)
    at async renderProject (file:///D:/quarto_book/.venv/Lib/site-packages/quarto_cli/bin/quarto.js:137151:23)
    at async _Command.actionHandler (file:///D:/quarto_book/.venv/Lib/site-packages/quarto_cli/bin/quarto.js:142481:24)
    at async _Command.execute (file:///D:/quarto_book/.venv/Lib/site-packages/quarto_cli/bin/quarto.js:102102:7)
    at async _Command.parseCommand (file:///D:/quarto_book/.venv/Lib/site-packages/quarto_cli/bin/quarto.js:101979:14)
    at async quarto4 (file:///D:/quarto_book/.venv/Lib/site-packages/quarto_cli/bin/quarto.js:187653:5)
    at async file:///D:/quarto_book/.venv/Lib/site-packages/quarto_cli/bin/quarto.js:187681:5
    at async file:///D:/quarto_book/.venv/Lib/site-packages/quarto_cli/bin/quarto.js:187536:14
    at async mainRunner (file:///D:/quarto_book/.venv/Lib/site-packages/quarto_cli/bin/quarto.js:187538:5)

[mcanouil]

@reckoner Please edit your original post with all the informations requested.

---

You can share a self-contained "working" (reproducible) Quarto document using the following syntax, i.e., using more backticks than you have in your document (usually four ````).
See https://quarto.org/bug-reports.html#small-is-beautiful-aim-for-a-single-document-with-10-lines.

If you have multiple files (and if it is absolutely required to have multiple files), please share as a Git repository.

R	Python
````qmd --- title: "Reproducible Quarto Document" format: html engine: knitr --- This is a reproducible Quarto document. {{< lipsum 1 >}} ```{r} x <- c(1, 2, 3, 4, 5) y <- c(1, 4, 9, 16, 25) plot(x, y) ``` {#fig-placeholder} {{< lipsum 1 >}} The end after @fig-placeholder. ````	````qmd --- title: "Reproducible Quarto Document" format: html engine: jupyter --- This is a reproducible Quarto document. {{< lipsum 1 >}} ```{python} import matplotlib.pyplot as plt x = [1, 2, 3, 4, 5] y = [1, 4, 9, 16, 25] plt.plot(x, y) plt.show() ``` {#fig-placeholder} {{< lipsum 1 >}} The end after @fig-placeholder. ````

Additionally and if not already given, please share the output of quarto check within a code block (i.e., using three backticks ```txt), see https://quarto.org/bug-reports.html#check.

[cderv]

@reckoner this is a LaTeX issue here. Something is wrong with your installed TinyTeX distribution.

I would try to remove it and install a fresh one again.

Did you do that already ?

[reckoner]

main...reckoner:quarto-cli:main

Fixed for me at that fork! Not sure how generally applicable it would be, though. Windows is tricky.

[cderv]

Interesting. I can guess the type of problem, but I would have preferred to have details on the real underlying problem.

I am a windows users and I never add problems. So something in the environment you are using is specific and makes quarto logic trip.

Several questions:

• It seems it is needed to add TinyTeX to PATH in your case. This is what --update-path arg in quarto install tinytex does if a user needs to install in PATH. How did you install TinyTeX in your case: using quarto install tinytex or another install method ?

  For now I can see we do use this
  

  quarto-cli/src/command/render/latexmk/texlive.ts

  Line 459 in 3e11b83

  const fmtutil = texLiveCmd("fmtutil-sys", context);

  and when TinyTeX is used, it should be absolute path used so no need to add to PATH

  quarto-cli/src/command/render/latexmk/texlive.ts

  Lines 375 to 388 in 3e11b83

  	export function texLiveCmd(cmd: string, context: TexLiveContext): TexLiveCmd {
  	if (context.preferTinyTex && context.hasTinyTex) {
  	if (context.binDir) {
  	return {
  	cmd,
  	fullPath: join(context.binDir, cmd),
  	};
  	} else {
  	return { cmd, fullPath: cmd };
  	}
  	} else {
  	return { cmd, fullPath: cmd };
  	}
  	}

  as we do fullPath: join(context.binDir, cmd)

  hence why I am wondering how you TinyTeX was installed.

• Using safeWindowsExec can indeed help solve this if there are some specific character in your paths, which was not currently handled. Can you confirm the fmtutil.fullPath, so where fmtutil-sys is exactly. I don't see one in the path shared in quarto check

   [>] Checking LaTeX....................OK
   Using: TinyTex
   Path: C:\Users\reckoner\AppData\Roaming\TinyTeX\bin\windows
   Version: 2026
  

Having the details or steps to reproduce the problem would definitely help us be sure we don't regress if we were to fix this.

Thank you!

Inlining the diff for reference

diff --git a/src/command/render/latexmk/texlive.ts b/src/command/render/latexmk/texlive.ts
index 923e6421966..f59bc832846 100644
--- a/src/command/render/latexmk/texlive.ts
+++ b/src/command/render/latexmk/texlive.ts
@@ -457,12 +457,23 @@ function tlmgrCommand(
 // https://tug.org/texlive/doc/fmtutil.html
 function fmtutilCommand(context: TexLiveContext) {
   const fmtutil = texLiveCmd("fmtutil-sys", context);
-  return execProcess(
-    {
-      cmd: fmtutil.fullPath,
-      args: ["--all"],
+  const pathSep = isWindows ? ";" : ":";
+  const env = context.binDir
+    ? {
+      ...Deno.env.toObject(),
+      PATH: `${context.binDir}${pathSep}${Deno.env.get("PATH") ?? ""}`,
+    }
+    : undefined;
+  const execFmtutil = (cmd: string[]) =>
+    execProcess({
+      cmd: cmd[0],
+      args: cmd.slice(1),
       stdout: "piped",
       stderr: "piped",
-    },
-  );
+      ...(env ? { env } : {}),
+    });
+  if (isWindows) {
+    return safeWindowsExec(fmtutil.fullPath, ["--all"], execFmtutil);
+  }
+  return execFmtutil([fmtutil.fullPath, "--all"]);
 }

[reckoner]

Great to find another Windows user 👍 the original problem I was having is that the tlmgr was trying to update the distribution while I was doing quarto render --to pdf filename.qmd. I installed tinytex with quarto install tinytex and it put it in the ~\AppData\Roaming\TinyTeX directory. I use quarto in a virtual environment so TinyTex/bin/windows is not in my path. The problem this creates is that when the tinytex distribution updates, it tries to run command from the TinyTex bin directory which is not in the path, hence the change. Also, there is a misleading message given about admin permissions required but this does not apply to the ~\AppData\Roaming\TinyTeX directory so that led me nowhere.

Hope that helps!

[cderv]

yes that helps understand. though I am puzzled on why I never encountered this problem...

I installed tinytex with quarto install tinytex and it put it in the ~\AppData\Roaming\TinyTeX directory. I use quarto in a virtual environment so TinyTex/bin/windows is not in my path.

quarto install tinytex does not put in PATH on purpose, and everything should work that way.
fmtutil-sys is supposed to be called using its full path so it should not need to be in PATH.
Unless something changed in TeX Live 2026 and could be an issue hidden there instead.

Also, there is a misleading message given about admin permissions required

Do you know what this message is or when it shows ?

Using safeWindowsExec can indeed help solve this if there are some specific character in your paths, which was not currently handled. Can you confirm the fmtutil.fullPath, so where fmtutil-sys is exactly. I don't see one in the path shared in quarto check

can you help me with this too please ?

Thank you!

[reckoner]

I think I got that message when it failed trying to update itself. Sorry, but I can't remember exactly where I saw it. I tried so many things to get it to work.

~\AppData\Roaming\TinyTeX\bin\windows is where fmtutil-sys.exe sits. Does that help?

[cderv]

I'll try to reproduce with what I have, and think of what I can add in quarto cli based on your solution. Thanks for sharing all this.