ERC check misses pins connected via certain labels

[Seth Hillbrand]

Running ERC check misses certain label connections. See attached schematic.

In the schematic, a tri-state pin is connected to a Power output pin (ERC Error) in 5 different ways. Direct connection, Global label and local label all work as expected.

Hierarchical labels and connections via ground symbols do not flag the connection as an ERC error.

All 5 cases are shown as ERC error in v5.1

Application: Eeschema
Version: (5.1.0-1542-g3135b6397-dirty), debug build
Libraries:
    wxWidgets 3.0.4
    libcurl/7.64.0 OpenSSL/1.1.1c zlib/1.2.11 libidn2/2.0.5 libpsl/0.20.2 (+libidn2/2.0.5) libssh2/1.8.0 nghttp2/1.36.0 librtmp/2.3
Platform: Linux 4.19.0-5-amd64 x86_64, 64 bit, Little endian, wxGTK
Build Info:
    wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.24
    Boost: 1.67.0
    OpenCASCADE Community Edition: 6.9.1
    Curl: 7.64.0
    Compiler: GCC 8.3.0 with C++ ABI 1013

Build settings:
    KICAD_SCRIPTING=ON
    KICAD_SCRIPTING_MODULES=ON
    KICAD_SCRIPTING_PYTHON3=ON
    KICAD_SCRIPTING_WXPYTHON=ON
    KICAD_SCRIPTING_WXPYTHON_PHOENIX=ON
    KICAD_SCRIPTING_ACTION_MENU=ON
    BUILD_GITHUB_PLUGIN=ON
    KICAD_USE_OCE=ON
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON
    KICAD_STDLIB_DEBUG=OFF
    KICAD_STDLIB_LIGHT_DEBUG=OFF
    KICAD_SANITIZE=OFF

[jean-pierre charras (jp-charras)]

@Jon
Have also a look to the demo "video":
most of ERC warnings are incorrect, especially:
"Pin connected to other pins, but not driven by any pin"
and
"Label not connected anywhere else in the schematic for bua and hierarchical bus labels"
for bus labels like DQ[0..31]: these bus labels are usually unique in a sheet (especially hierarchical bus label), but they are connected by members so such a warning is incorrect.

(However the netlist is good).
Thanks.

[Jon Evans (craftyjon)]

I will check it out, this was working earlier so perhaps there was a recent regression

[KiCad Janitor (kicad-janitor)]

KiCad bug tracker has moved to Gitlab. This report is now available here: https://gitlab.com/kicad/code/kicad/-/issues/2555