docs: fix build taking too long

CHANGELOG.md

@@ -11,9 +11,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 Maintenance update:
 
+### Added
+
+- `PROLIF_N_JOBS` environment variable to control multiprocessing during the
+  documentation build.
+
 ### Changed
 
-- Updated CI pipelines to test on Python 3.8, 3.10 and 3.12
+- Updated CI pipelines to test on Python 3.8, 3.10 and 3.12.
 
 ### Fixed
 

docs/conf.py

@@ -54,7 +54,7 @@
 ]
 nb_execution_allow_errors = False
 nb_execution_raise_on_error = True
-nb_execution_timeout = 180
+nb_execution_timeout = 240
 
 mathjax_path = "https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/MathJax.js?config=TeX-AMS-MML_HTMLorMML"
 autosectionlabel_prefix_document = True

prolif/fingerprint.py

@@ -24,6 +24,8 @@
     fp = prolif.Fingerprint.from_pickle("fingerprint.pkl")
 
 """
+
+import os
 import warnings
 from collections.abc import Sized
 from functools import wraps
@@ -462,6 +464,8 @@ def run(
             raise ValueError("converter_kwargs must be a list of 2 dicts")
 
         converter_kwargs = converter_kwargs or ({}, {})
+        if n_jobs is None:
+            n_jobs = os.environ.get("PROLIF_N_JOBS", n_jobs)
         if residues == "all":
             residues = list(Molecule.from_mda(prot, **converter_kwargs[1]).residues)
         if n_jobs != 1: