Doing something like
(MicFileResourceReference fromFileRef:
'C:/cygwin64/home/driolar/Booklet-PharoGraphs-master/Chapters/Chapter1/figures/Paris_Metro_map_1024.pdf' asFileReference) fullName
leads to
>>> '/C:/cygwin64/home/driolar/Booklet-PharoGraphs-master/Chapters/Chapter1/figures/Paris_Metro_map_1024.pdf'.
Note the leading slash before the drive letter that makes the path invalid on Windows.
As a consequence, TeX cannot find the figures when building a PDF on Windows.
The leading slash is set in:
MicAbsoluteResourceReference >> path
"return the path part of my uri"
^ '/', uri path