Add distribution for dev user base.

Author: fangerer

mx.graalpython/mx_graalpython.py

@@ -112,6 +112,7 @@ def do_run_python(args, extra_vm_args=None, env=None, jdk=None, **kwargs):
             check_vm()
 
     dists = ['GRAALPYTHON', 'TRUFFLE_NFI', 'SULONG']
+    env["PYTHONUSERBASE"] = mx_subst.path_substitutions.substitute("<path:PYTHON_USERBASE>")
 
     vm_args, graalpython_args = mx.extract_VM_args(args, useDoubleDash=True, defaultAllVMArgs=False)
     graalpython_args, additional_dists = _extract_graalpython_internal_options(graalpython_args)
@@ -147,7 +148,7 @@ def do_run_python(args, extra_vm_args=None, env=None, jdk=None, **kwargs):
         vm_args += extra_vm_args
 
     vm_args.append("com.oracle.graal.python.shell.GraalPythonMain")
-    return mx.run_java(vm_args + graalpython_args, jdk=jdk, **kwargs)
+    return mx.run_java(vm_args + graalpython_args, jdk=jdk, env=env, **kwargs)
 
 
 def punittest(args):

mx.graalpython/suite.py

@@ -289,6 +289,7 @@
             "distDependencies": [
                 "sdk:GRAAL_SDK",
                 "sdk:LAUNCHER_COMMON",
+                "PYTHON_USERBASE",
             ],
             "description": "GraalPython launcher",
         },
@@ -383,5 +384,15 @@
             },
             "maven": False,
         },
+
+        "PYTHON_USERBASE": {
+            "native": True,
+            "platformDependent": False,
+            "description": "Blub",
+            "layout": {
+                "./README.md": "string:User base directory for development purpose.",
+            },
+            "maven": False,
+        },
     },
 }