runscript.exe and process termination
Paulo Roberto Massa Cereda
cereda.paulo at gmail.com
Sat Sep 19 11:51:09 CEST 2020
Dear friends in the TL list,
TeX Live on Windows uses wrappers around common tools (e.g. latexmk,
arara etc.) based on the runscript.exe program (runscript.tlu). It is a
clever approach to provide a consistent, unified entry point to deploy
binaries in the Windows environment.
While working on issues opened for arara, there were a few mentions that
process killing on Windows did not work as expected. We (the island)
decided to investigate what was going on.
To give you some context, we summarized our findings in
These findings show one real problem on Windows: Processes started from
editors based on Qt's process management cannot be easily killed because
their subprocesses will not be terminated (that is how the Windows API
Now, while we know that especially in this case it is not a problem of
the wrapper script per se, we would like to point out some code excerpts
from popular editors:
- TeXworks kills processes using Qt's kill method which, as detailed in
the issue, does not kill subprocesses:
- TeXmaker kills processes with the same method (line 8165 in
texmaker.cpp of the current sources of version 5.0.4).
- TeXStudio has written a wrapper (ProcessX) around QProcess but uses
the same approach for killing applications.
At least three of the more common editors use Qt's method of killing
processes which will not kill child processes on Windows (because
Windows does not enforce this concept like unices). That means that
killing the exe wrapper will actually not propagate the kill signal to
the actual process that was supposed to be killed which is kind of
We (the island) were wondering if it would be a good idea for the
runscript.exe wrapper to kill underlying processes on termination to
remove the additional “layer” of processes kept alive. I don't know much
of the inner workings of the wrapper, so apologies to the wrapper
maintainers if we are asking something too troublesome to implement, as
we really do not want to add more complexity.
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