Script compiled with pyinstaller is missing a .dll file, when the file is manually copied in the program's folder it just dies - pyinstaller

Question

I have a python script which is basically a graphic interface (pysimpleguy) to a mysql database.
I am working in python 3.8; my dependencies are:
PySimpleGUI 4.55.1
sqlalchemy 1.3.20
pymysql 1.0.2
pandas 1.1.3
regex 2020.10.15
pillow 8.0.1
The code works and I'd like to compile it to .exe to distribute it to users in my organization.
I tried to compile it with:
pyinstaller -D .\db_interface_v3.6.1_release.py --debug=imports
However, pyinstaller throws some errors when compiling:
201667 INFO: Building COLLECT COLLECT-00.toc
Traceback (most recent call last):
File "c:\users\spit\anaconda3\lib\runpy.py", line 194, in _run_module_as_main
return _run_code(code, main_globals, None,
File "c:\users\spit\anaconda3\lib\runpy.py", line 87, in _run_code
exec(code, run_globals)
File "C:\Users\Spit\anaconda3\Scripts\pyinstaller.exe\__main__.py", line 7, in <module>
File "c:\users\spit\anaconda3\lib\site-packages\PyInstaller\__main__.py", line 124, in run
run_build(pyi_config, spec_file, **vars(args))
File "c:\users\spit\anaconda3\lib\site-packages\PyInstaller\__main__.py", line 58, in run_build
PyInstaller.building.build_main.main(pyi_config, spec_file, **kwargs)
File "c:\users\spit\anaconda3\lib\site-packages\PyInstaller\building\build_main.py", line 782, in main
build(specfile, kw.get('distpath'), kw.get('workpath'), kw.get('clean_build'))
File "c:\users\spit\anaconda3\lib\site-packages\PyInstaller\building\build_main.py", line 714, in build
exec(code, spec_namespace)
File "C:\Users\Spit\Desktop\DIPEx db parser\db_interface_v3.6.1_release.spec", line 37, in <module>
coll = COLLECT(exe,
File "c:\users\spit\anaconda3\lib\site-packages\PyInstaller\building\api.py", line 818, in __init__
self.__postinit__()
File "c:\users\spit\anaconda3\lib\site-packages\PyInstaller\building\datastruct.py", line 155, in __postinit__
self.assemble()
File "c:\users\spit\anaconda3\lib\site-packages\PyInstaller\building\api.py", line 866, in assemble
shutil.copy(fnm, tofnm)
File "c:\users\spit\anaconda3\lib\shutil.py", line 415, in copy
copyfile(src, dst, follow_symlinks=follow_symlinks)
File "c:\users\spit\anaconda3\lib\shutil.py", line 261, in copyfile
with open(src, 'rb') as fsrc, open(dst, 'wb') as fdst:
FileNotFoundError: [Errno 2] No such file or directory: 'C:\\Users\\Spit\\Desktop\\DIPEx db parser\\dist\\db_interface_v3.6.1_release\\share\\jupyter\\lab\\staging\\node_modules\\.cache\\terser-webpack-p
lugin\\content-v2\\sha512\\2e\\ba\\cfce62ec1f408830c0335f2b46219d58ee5b068473e7328690e542d2f92f2058865c600d845a2e404e282645529eb0322aa4429a84e189eb6b58c1b97c1a'
If I try to run the compiled exe, I get an error regarding a specific .dll:
INTEL MKL ERROR: Impossibile trovare il modulo specificato. mkl_intel_thread.dll.
Intel MKL FATAL ERROR: Cannot load mkl_intel_thread.dll.
If I take this missing .dll from my Anaconda environment and copy it into the program's folder, when I try to run the .exe again it just dies without further messages:
import 'numpy.ma' # <pyimod03_importers.FrozenImporter object at 0x000001F6A455BEE0>
PS C:\Users\Spit\Desktop\DIPEx db parser\dist\db_interface_v3.6.1_release>
Any idea on how to sort it out?
Thanks!

Answer 1

Sorted out. As a future reference if someone stumbles upon this question, the error is caused by Windows' PATH_MAX limitation, preventing pyinstaller to find all the necessary files.
In order to disable said limitation: https://learn.microsoft.com/en-us/windows/win32/fileio/maximum-file-path-limitation?tabs=cmd
Kudos to https://github.com/bwoodsend