Description of the issue

When using PyInstaller to bundle submodules of a namespace package, where each submodule is its own module (see the example at PyPA, none of the submodules appear under the namespace when iterating over the namespace using pkgutil.iter_modules. Using from namespace import submodule does work, however.

Printing the namespace module after importing it in a script and from an exe shows two different results:

import namespace
print(namespace)
# Script output: <module 'subpackages' (namespace)>
# PyInstaller output: <module 'namespace' from 'path_to_namespace/__init__.pyc'>

In addition, for the code example linked below, when I ran PyInstaller with --debug all and looked in dist/pyi_ns_issue/subpackages, only submod_b (which is explicitly imported unlike submod_a) is listed.

Context information (for bug reports)

• Output of pyinstaller --version: 4.0

• Version of Python: e.g. 3.7.5 and 3.8.2

• Platform: Ubuntu 20.04.1 LTS

• Did you also try this on another platform? Does it work there? Encountered the same issue on Windows 10 Enterprise 1809

• try the latest development version, using the following command:

pip install https://github.com/pyinstaller/pyinstaller/archive/develop.zip

• follow all the instructions in our "If Things Go Wrong" Guide
  (https://github.com/pyinstaller/pyinstaller/wiki/If-Things-Go-Wrong) and

Make sure everything is packaged correctly

• start with clean installation
• use the latest development version
• Run your frozen program from a command window (shell) — instead of double-clicking on it
• Package your program in --onedir mode
• Package without UPX, say: use the option --noupx or set upx=False in your .spec-file
• Repackage you application in verbose/debug mode. For this, pass the option --debug to pyi-makespec or pyinstaller or use EXE(..., debug=1, ...) in your .spec file.

A minimal example program which shows the error

I've made a repo with a mimimal example at: https://github.com/SpenserHaddad/pyinstaller-namespace-issue-repro

Here's the offending code from the repo:

impl_modules = pkgutil.iter_modules(subpackages.__path__, subpackages.__name__ + ".")
# impl_modules is an "empty" generator, and the nothing will happen in the loop below
for mod in impl_modules:
    loaded_mod = importlib.import_module(mod.name)
    print(loaded_mod.sayhi())

Stacktrace / full error message

(paste text here)

Please also see https://github.com/pyinstaller/pyinstaller/wiki/How-to-Report-Bugs
for more about what would use to solve the issue.