lilypond-book.py can hang on Windows 10; I know why; I need help to fix it

[Jean Abou Samra]

> Back on January 12, 2021, I wrote to this forum about a problem I was 
> having running the example from 
> https://lilypond.org/doc/v2.19/Documentation/usage/an-example-of-a-musicological-document 
> <https://lilypond.org/doc/v2.19/Documentation/usage/an-example-of-a-musicological-document> 
> for embedding Lilypond code inside a LaTeX document.  The python 
> script, lilypond-book.py starts up, I get a few lines of output, and 
> then the program hangs.  One reader of this forum wrote to me that the 
> script works for him, so I knew there was something about my 
> installation of Lilypond or version of Python or something.  By the 
> way, I had no problems with lilypond-book on Linux.
>
> Today I began to read through the python code that runs when 
> lilypond-book.py is invoked.  The authors of the python code cleverly, 
> in python-latex.py, create a temporary .tex file that is run with 
> pdflatex to extract some information about the linewidth and column 
> separation.  The authors import the python library tempfile and use 
> the method mkstemp to create the filename for the temporary file.  I 
> sprinkled some print functions into the python code to trace what was 
> going on and discovered that the temporary file gets created on my 
> Windows 10 system in:
> C:\Users\<user_id>\AppData\Local\Temp
> where <user_id> is my Windows user account name.  My user_id has 9 
> characters in it, for example DanABCDEF. However, the path for the 
> temporary file was shown by one of my debugging print statements to be 
> C:\Users\DanABCD~F\AppData\Local\Temp.  This is an old DOS "8.3" file 
> naming convention DOS used to deal with "long" path and filenames.
>
> After creating this temporary file, pdflatex tries to run on it and 
> pdflatex gags because it can't find the file; pdflatex can't deal with 
> the "~" in the file pathname.  The process that is running pdflatex 
> tries to prompt me to enter another name.  However that process' 
> output isn't shown and all I see is a hung program.
>
> So because my user_id is more than 8 characters long the temporary 
> file pathname gets trashed.  I bet the user who wrote me that 
> lilypond-book worked for him has a short Windows user_id!
>
> I've looked around a little bit in Python to see if there are options 
> when the mkstemp is called to create a Windows temporary filename 
> without the "8.3" legacy DOS naming convention.  I didn't see 
> anything.  Some of my Google searches suggested there is an additional 
> library that could be imported that deals with long filenames.
>
> I am turning this over to any follower of this forum who is more 
> skilled than I am in Python to come up with a fix.
>
> By the way, I am using Lilypond and lilypond-book to engrave a short 
> piece of music into a lab assignment handout sheet that I create in 
> LaTeX that I give to my digital signal processing (DSP) students.  
> They have to synthesize the music on a DSP hardware board.
>
> Thank you for your help.
>
> Dan

Hi,

Wow, Windows is even worse than I thought!

Maybe try the following diff (but I don't have a Windows machine to test 
it):


diff --git a/python/book_latex.py b/python/book_latex.py
index 2530fd75ba..1e2cfb36e4 100644
--- a/python/book_latex.py
+++ b/python/book_latex.py
@@ -204,7 +204,7 @@ def get_latex_textwidth(source, global_options):
     preamble = source[:m.start(0)]
     latex_document = LATEX_INSPECTION_DOCUMENT % {'preamble': preamble}

-    (handle, tmpfile) = tempfile.mkstemp('.tex')
+    (handle, tmpfile) = tempfile.mkstemp('.tex', dir=".") # create 
temporary file in current directory
     tmpfileroot = os.path.splitext(tmpfile)[0]
     tmpfileroot = os.path.split(tmpfileroot)[1]
     auxfile = tmpfileroot + '.aux'
@@ -216,7 +216,7 @@ def get_latex_textwidth(source, global_options):

     progress(_("Running `%s' on file `%s' to detect default page 
settings.\n")
              % (global_options.latex_program, tmpfile))
-    cmd = '%s %s' % (global_options.latex_program, tmpfile)
+    cmd = '%s %s' % (global_options.latex_program, 
os.path.relpath(tmpfile)) # convert to relative path so there isn't any 
tilde
     debug("Executing: %s\n" % cmd)
     run_env = os.environ.copy()
     run_env['LC_ALL'] = 'C'


In general, I would not recommend using lilypond-book. lyLuaTeX is so 
much better: https://mirrors.ircam.fr/pub/CTAN/support/lyluatex/lyluatex.pdf

Best,
Jean