Although statements in subprocess get executed, coverage still reports them as missing.

[flixman]

Describe the bug In my flask project, running through pytest with the pytest-flask plugin, a subprocess gets started. I get two .coverage..* files that get generated, but the report shows lines as missing. If I run the same tests on a debugger and set a breakpoint there, those lines are hit... but still report missing.

UPDATE: There is one of the methods on a specific file in which a single line is reported missing (out of 5). I have checked the plugin starting the subprocess, (pytest-flask, file live_server.py) and it sends a SIGINT to the process before calling the join (which seems to be aligned with coverage recommendations).

To Reproduce How can we reproduce the problem? Please be specific. Don't link to a failing CI job. Answer the questions below:

1. What version of Python are you using? 3.10.8
2. What version of coverage.py shows the problem?

   -- sys -------------------------------------------------------
              coverage_version: 7.0.1
               coverage_module: ~/venv/lib/python3.10/site-packages/coverage/__init__.py
                        tracer: -none-
                       CTracer: available
          plugins.file_tracers: -none-
           plugins.configurers: -none-
     plugins.context_switchers: -none-
             configs_attempted: .coveragerc
                  configs_read: ~/.coveragerc
                   config_file: ~/.coveragerc
               config_contents: b"[run]\nbranch = true\nparallel = true\nconcurrency = multiprocessing\nsigterm = true\nomit =\n    backend/tests/*\n    backend/blueprints/test.py\n    backend/blueprints/checkout.py\n\n[report]\nfail_under = 90\nshow_missing = True\n\n# Regexes for lines to exclude from consideration\nexclude_lines =\n    # Have to re-enable the standard pragma\n    pragma: no cover\n\n    # Don't complain about missing debug-only code:\n    def __repr__\n    if self\\.debug\n\n    # Don't complain if non-runnable code isn't run:\n    if 0:\n    if __name__ == .__main__.:\n\n    # Don't complain about abstract methods, they aren't run:\n    @(abc\\.)?abstractmethod\n"
                     data_file: -none-
                        python: 3.10.8 (main, Nov  1 2022, 14:18:21) [GCC 12.2.0]
                      platform: Linux-6.0.12-arch1-1-x86_64-with-glibc2.36
                implementation: CPython
                    executable: ~/venv/bin/python
                  def_encoding: utf-8
                   fs_encoding: utf-8
                           pid: 154712
                           cwd: ~
                          path: ~/venv/bin
                                /usr/lib/python310.zip
                                /usr/lib/python3.10
                                /usr/lib/python3.10/lib-dynload
                                ~/venv/lib/python3.10/site-packages
                   environment: HOME = ~
                  command_line: ~/venv/bin/coverage debug sys
               sqlite3_version: 2.6.0
        sqlite3_sqlite_version: 3.40.0
            sqlite3_temp_store: 0
       sqlite3_compile_options: ATOMIC_INTRINSICS=1, COMPILER=gcc-12.2.0, DEFAULT_AUTOVACUUM,
                                DEFAULT_CACHE_SIZE=-2000, DEFAULT_FILE_FORMAT=4,
                                DEFAULT_JOURNAL_SIZE_LIMIT=-1, DEFAULT_MMAP_SIZE=0, DEFAULT_PAGE_SIZE=4096,
                                DEFAULT_PCACHE_INITSZ=20, DEFAULT_RECURSIVE_TRIGGERS,
                                DEFAULT_SECTOR_SIZE=4096, DEFAULT_SYNCHRONOUS=2,
                                DEFAULT_WAL_AUTOCHECKPOINT=1000, DEFAULT_WAL_SYNCHRONOUS=2,
                                DEFAULT_WORKER_THREADS=0, ENABLE_COLUMN_METADATA, ENABLE_DBSTAT_VTAB,
                                ENABLE_FTS3, ENABLE_FTS3_PARENTHESIS, ENABLE_FTS3_TOKENIZER, ENABLE_FTS4,
                                ENABLE_FTS5, ENABLE_MATH_FUNCTIONS, ENABLE_RTREE, ENABLE_STMTVTAB,
                                ENABLE_UNLOCK_NOTIFY, HAVE_ISNAN, MALLOC_SOFT_LIMIT=1024, MAX_ATTACHED=10,
                                MAX_COLUMN=2000, MAX_COMPOUND_SELECT=500, MAX_DEFAULT_PAGE_SIZE=8192,
                                MAX_EXPR_DEPTH=10000, MAX_FUNCTION_ARG=127, MAX_LENGTH=1000000000,
                                MAX_LIKE_PATTERN_LENGTH=50000, MAX_MMAP_SIZE=0x7fff0000,
                                MAX_PAGE_COUNT=1073741823, MAX_PAGE_SIZE=65536, MAX_SQL_LENGTH=1000000000,
                                MAX_TRIGGER_DEPTH=1000, MAX_VARIABLE_NUMBER=250000, MAX_VDBE_OP=250000000,
                                MAX_WORKER_THREADS=8, MUTEX_PTHREADS, SECURE_DELETE, SYSTEM_MALLOC,
                                TEMP_STORE=1, THREADSAFE=1

3. What versions of what packages do you have installed?

   attrs==22.2.0
   certifi==2022.12.7
   charset-normalizer==2.1.1
   click==8.1.3
   exceptiongroup==1.1.0
   Flask==2.2.2
   Flask-Cors==3.0.10
   Flask-Login==0.6.2
   Flask-SQLAlchemy==3.0.2
   Flask-WTF==1.0.1
   greenlet==2.0.1
   gunicorn==20.1.0
   idna==3.4
   iniconfig==1.1.1
   itsdangerous==2.1.2
   Jinja2==3.1.2
   MarkupSafe==2.1.1
   numpy==1.24.1
   packaging==22.0
   pluggy==1.0.0
   psycopg2==2.9.5
   pydot==1.4.2
   pyparsing==3.0.9
   pytest==7.2.0
   pytest-flask==1.2.0
   python-dotenv==0.21.0
   PyYAML==6.0
   requests==2.28.1
   six==1.16.0
   SQLAlchemy==1.4.45
   SQLAlchemy-Utils==0.39.0
   stripe==5.0.0
   tomli==2.0.1
   urllib3==1.26.13
   Werkzeug==2.2.2
   WTForms==3.0.1

4. What code shows the problem? It is a private repo, I cannot share :-/
5. What commands did you run?

   rm -f .coverage.*
   coverage run -m pytest
   coverage combine
   coverage report 

Expected behavior I get the information related to the coverage of the statements run by the subprocess that is running the flask server.

[nedbat]

I have checked the plugin starting the subprocess, (pytest-flask, file live_server.py) and it sends a SIGINT to the process before calling the join (which seems to be aligned with coverage recommendations).

Have you tried setting the [run] sigterm = true setting? (docs)

[flixman]

Hi @nedbat Indeed, this is my .coveragerc:

[run]
branch = true
parallel = true
concurrency = multiprocessing
sigterm = true
omit =
    backend/tests/*
    backend/blueprints/test.py
    backend/blueprints/checkout.py

[report]
fail_under = 90
show_missing = True

# Regexes for lines to exclude from consideration
exclude_lines =
    # Have to re-enable the standard pragma
    pragma: no cover

    # Don't complain about missing debug-only code:
    def __repr__
    if self\.debug

    # Don't complain if non-runnable code isn't run:
    if 0:
    if __name__ == .__main__.:

    # Don't complain about abstract methods, they aren't run:
    @(abc\.)?abstractmethod

Is there any way, if I set up a breakpoint inside the subprocess, to confirm that coverage is working there?

[nedbat]

Check if the server is started with debug=True: that can run your code inside a debugger, which interferes with coverage.py data collection. See #1663.