venv: Install in user venv the same version of ipykernel that Mu is running

mu/wheels/__init__.py

@@ -8,6 +8,7 @@
 import subprocess
 import tempfile
 import zipfile
+import pkg_resources
 
 from .. import __version__ as mu_version
 
@@ -40,9 +41,6 @@ class WheelsBuildError(WheelsError):
     ("pgzero", ("pgzero>=1.2.1",)),
     # Lock Werkzeug to < 3.0.0: import flask fails, otherwise.
     ("flask", ("flask==2.0.3", "Werkzeug<3.0.0")),
-    # The version of ipykernel here should match to the version used by
-    # qtconsole at the version specified in setup.py
-    ("ipykernel", ("ipykernel>=5.5.6",)),
 ]
 
 
@@ -90,7 +88,33 @@ def remove_dist_files(dirpath, logger):
         os.remove(rm_filepath)
 
 
+def get_mu_package_version(package_name):
+    """Get the version of a package in Python environment running Mu."""
+    try:
+        version = pkg_resources.get_distribution(package_name).version
+        return version
+    except pkg_resources.DistributionNotFound:
+        logger.error(
+            "Package {} not found in Mu environment".format(package_name)
+        )
+        raise
+
+
 def pip_download(dirpath, logger, additional_flags=[]):
+    """Download wheels for the packages to be installed in the user venv."""
+    # ipykernel needs to be added to the user venv to launch the iPython REPL
+    # from within that environment.
+    # The ipykernel version must match the version installed in the Mu
+    # environment or the user venv kernel might fail (Kernel died, restarting).
+    ipykernel_version = get_mu_package_version("ipykernel")
+    logger.info("Detecting Mu ipykernel version: {}".format(ipykernel_version))
+    mode_packages.append(
+        (
+            "ipykernel",
+            ("ipykernel=={}".format(ipykernel_version),),
+        )
+    )
+
     for name, pip_identifiers, *extra_flags in mode_packages:
         logger.info(
             "Running pip download for %s / %s / %s / %s",

setup.py

@@ -34,10 +34,10 @@
     "PyQtChart==5.15.6"
     + '; sys_platform != "linux" '
     + 'or ("arm" not in platform_machine and "aarch" not in platform_machine)',
-    # FIXME: Needed for qtconsole, this is the latest wheel in armv7l for
+    # Needed for qtconsole, this is the latest wheel in armv7l for
     # Python 3.7 (Buster), otherwise it tries to build from source and fails.
     "pyzmq<=26.0.3",
-    # We are using an internal method of jupyter_client, that changed in v7
+    # We are using an internal method of jupyter_client that changed in v7
     # QtKernelManager._launch_kernel() returning a KernelProvisionerBase
     # https://github.com/jupyter/jupyter_client/commit/516d9df270b2e4603ee0ecd986554cb5fe1c2940
     "jupyter-client<7",