When I encounter something like this (especially with a nightly build) I am reluctant to write a bug report unless I can easily reproduce it. But with the likelihood that someone may eventually be able to do so, I feel I ought to mention it.
Last night I ran DRC on my board and it found a large number of violations. I use a default 40 mil track width, and use custom widths where needed. It seems that all of my custom track widths were somehow “forgotten”. This resulted in many shorts between IC pins. The other weird result (insult to injury) was that when I started to manually edit the track widths, KiCad notified me that it was changing (I think it was all of the shorted pins) to the same net. Fortunately this was corrected when I re-ran “update the pcb from the schematic.” I am finished with this part of my process now so I do not see this dialog box to post an image of it.
I probably updated my version during all this. I also added and inserted another IC into the schematic and board.
This is my present nightly build:
Application: Pcbnew Version: (5.99.0-1137-gcc47062b1), release build Libraries: wxWidgets 3.0.4 libcurl/7.66.0 OpenSSL/1.1.1d (Schannel) zlib/1.2.11 brotli/1.0.7 libidn2/2.2.0 libpsl/0.21.0 (+libidn2/2.1.1) nghttp2/1.39.2 Platform: Windows 8 (build 9200), 64-bit edition, 64 bit, Little endian, wxMSW Build Info: Build date: Mar 23 2020 21:57:36 wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8) Boost: 1.71.0 OpenCASCADE Community Edition: 6.9.1 Curl: 7.66.0 Compiler: GCC 9.2.0 with C++ ABI 1013 Build settings: KICAD_SCRIPTING=ON KICAD_SCRIPTING_MODULES=ON KICAD_SCRIPTING_PYTHON3=OFF KICAD_SCRIPTING_WXPYTHON=ON KICAD_SCRIPTING_WXPYTHON_PHOENIX=OFF KICAD_SCRIPTING_ACTION_MENU=ON BUILD_GITHUB_PLUGIN=ON KICAD_USE_OCE=ON KICAD_USE_OCC=OFF KICAD_SPICE=ON