set JULIA_PYTHONCALL_EXE instead of JULIA_PYTHONCALL_EXECUTABLE in juliacall (#814)

JuliaCall set JULIA_PYTHONCALL_EXECUTABLE, which nothing reads, so the
Python executable was not visible to Julia at the process level and
child Julia processes resolved a new CondaPkg environment.

Fixes #813

Co-authored-by: Miles Cranmer <miles.cranmer@gmail.com>

Author: MilesCranmerBot

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## Unreleased
 * Bug fix: avoid precompilation cache miss when `check_bounds` option set.
+* Bug fix: `juliacall` set the environment variable `JULIA_PYTHONCALL_EXECUTABLE`
+  instead of `JULIA_PYTHONCALL_EXE`, so child Julia processes resolved a new
+  CondaPkg environment.
 
 ## 0.9.35 (2026-06-08)
 * Add option `lib` to JuliaCall. Setting this will skip the discovery subprocess.

pysrc/juliacall/__init__.py

@@ -256,7 +256,7 @@ def args_from_config(config):
 
     # override some environment variables
     # we do this here because PythonCall is initialised during jl_init if it is in a sysimg
-    os.environ['JULIA_PYTHONCALL_EXECUTABLE'] = sys.executable or ''
+    os.environ['JULIA_PYTHONCALL_EXE'] = sys.executable or ''
     os.environ['__JULIA_PYTHONCALL_EMBEDDED_LIBPTR__'] = hex(c.pythonapi._handle)
 
     # initialise julia