test: interface_ipc.py might start skipping if installed capnp version changes #34016

1. 
   fanquake commented at 2:38 pm on December 5, 2025: member

   Noticed this on a Fedora (Rawhide) Box that has capnp 1.2.0 (recently updated from 1.1.0) and pycapnp 2.1.0 installed, but was skipping interface_ipc.py as if the Python module was not available. The failure was that pycanp 2.1.0 tries to load an older shared lib, and fails:

    0Remaining jobs: [interface_ipc.py]
    11/1 - interface_ipc.py failed, Duration: 0 s
    2
    3stdout:
    4
    5
    6stderr:
    7Traceback (most recent call last):
    8  File "/root/ci_scratch/build/test/functional/interface_ipc.py", line 20, in <module>
    9    import capnp  # type: ignore[import] # noqa: F401
   10    ^^^^^^^^^^^^
   11  File "/usr/local/lib64/python3.14/site-packages/capnp/__init__.py", line 36, in <module>
   12    from .version import version as __version__
   13  File "/usr/local/lib64/python3.14/site-packages/capnp/version.py", line 1, in <module>
   14    from .lib.capnp import _CAPNP_VERSION_MAJOR as LIBCAPNP_VERSION_MAJOR  # noqa: F401
   15    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   16ImportError: libcapnpc.so.1.0.1: cannot open shared object file: No such file or directory
   

   We catch this and skip as if the module isn’t available. Updating to pycapnp 2.2.1 solved the issue.

2. fanquake added the label Tests on Dec 5, 2025
3. 
   ryanofsky commented at 3:46 pm on December 5, 2025: contributor

   Maybe this would get the failure to be reported properly:

   0--- a/test/functional/interface_ipc.py
   1+++ b/test/functional/interface_ipc.py
   2@@ -19,7 +19,7 @@ from test_framework.wallet import MiniWallet
   3 # Test may be skipped and not have capnp installed
   4 try:
   5     import capnp  # type: ignore[import] # noqa: F401
   6-except ImportError:
   7+except ModuleNotFoundError:
   8     pass [@asynccontextmanager](/bitcoin-bitcoin/contributor/asynccontextmanager/)
   

4. 
   fanquake commented at 4:01 pm on December 5, 2025: member

   @ryanofsky yes, that works.
5. fanquake referenced this in commit 905dfdee86 on Jan 26, 2026
6. fanquake renamed this:
   test: `interface_ipc.py` (might?) start skipping if installed capnp version changes
   test: `interface_ipc.py` might start skipping if installed capnp version changes
   on Jan 26, 2026
7. 
   hebasto commented at 1:09 pm on January 26, 2026: member

   Noticed this on a Fedora (Rawhide) Box that has capnp 1.2.0 (recently updated from 1.1.0) and pycapnp 2.1.0 installed, but was skipping interface_ipc.py as if the Python module was not available. The failure was that pycanp 2.1.0 tries to load an older shared lib, and fails:

    0Remaining jobs: [interface_ipc.py]
    11/1 - interface_ipc.py failed, Duration: 0 s
    2
    3stdout:
    4
    5
    6stderr:
    7Traceback (most recent call last):
    8  File "/root/ci_scratch/build/test/functional/interface_ipc.py", line 20, in <module>
    9    import capnp  # type: ignore[import] # noqa: F401
   10    ^^^^^^^^^^^^
   11  File "/usr/local/lib64/python3.14/site-packages/capnp/__init__.py", line 36, in <module>
   12    from .version import version as __version__
   13  File "/usr/local/lib64/python3.14/site-packages/capnp/version.py", line 1, in <module>
   14    from .lib.capnp import _CAPNP_VERSION_MAJOR as LIBCAPNP_VERSION_MAJOR  # noqa: F401
   15    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   16ImportError: libcapnpc.so.1.0.1: cannot open shared object file: No such file or directory
   

   We catch this and skip as if the module isn’t available. Updating to pycapnp 2.2.1 solved the issue.

   I can’t reproduce the issue:

    0# dnf info capnproto 2>&1 | grep Version
    1Version         : 1.3.0
    2# pip show pycapnp | grep Version
    3Version: 2.1.0
    4# ./build/test/functional/test_runner.py interface_ipc
    5Temporary test directory at /tmp/test_runner_₿_🏃_20260126_130625
    6Remaining jobs: [interface_ipc.py]
    71/1 - interface_ipc.py passed, Duration: 7 s
    8
    9TEST             | STATUS    | DURATION
   10
   11interface_ipc.py | ✓ Passed  | 7 s
   12
   13ALL              | ✓ Passed  | 7 s (accumulated) 
   14Runtime: 7 s
   

8. 
   fanquake commented at 1:14 pm on January 26, 2026: member

   I can’t reproduce the issue:

   It’s not clear what you tested here. You need to test the capnp shared libs being updated, without updating pycapnp.

9. 
   hebasto commented at 1:20 pm on January 26, 2026: member

   I can’t reproduce the issue:

   It’s not clear what you tested here.

   I’ve tested this claim: “The failure was that pycanp 2.1.0 tries to load an older shared lib, and fails:”. It wasn’t clear that updating capnp is necessary for observing the issue.

   You need to test the capnp shared libs being updated, without updating pycapnp.

   Well, this could be tricky as the Rawhide repository doesn’t keep the previous capnproto version.

Contributors
fanquake ryanofsky hebasto

Labels
Tests