I've been seeing an intermittent crash in setup_process_coding_systems (crash traces are attached). It seems to most frequently happen from create_process -> setup_process_coding_systems, but that may just be due to my frequent usage of `helm-do-ag-project-root'. For the attached crash_2020-01-15_1_create_process.log, it happened when using `helm-do-ag-project-root', which takes input from the minibuffer and runs an external `ag` (the_silver_searcher) process to search the current project (in this case, a git repo) and display/refresh the results as I type in the minibuffer. For the other crash logs, unfortunately I didn't record what I was doing at the time. But IIRC most of them were from `helm-do-ag-project-root`. I have also seen this crash happen in other packages: `magit`, when opening a magit-status buffer (which runs various git commands, e.g. `git status`); and when starting up an external language server process from `lsp-go` (although I've most frequently seen this from helm). I've also had at least one crash in `setup_process_coding_systems' that was called by `connect_network_socket' (see crash_2020-01-06_2.log attached). I believe this crash happened when I opened a `go-mode' buffer and `lsp-mode' was starting up an external language server process, but I'm not 100% sure of that. Unfortunately it's a similar situation to bug#38822--I started seeing this at some point after recompiling emacs from source, somewhere approx. between cbc10ec71e9f189e8d6fd5c6927aec4872e0fd96 and 0bc00cda3cb6e765b0e1f0105edf75425bce13c9 (which is a long range of commits unfortunately). I've also recompiled from source from the emacs-27 branch a few times since then, but it doesn't seem to have affected how often I get this crash (my most recent build was @ 16eaaa07e6ba6a41ccdc562dcb52fc87c38f8083, with a small patch applied from https://debbugs.gnu.org/cgi/bugreport.cgi?bug=38748#92 to try fixing a seemingly-unrelated crash to this one--see bug#38822). I haven't managed to reproduce this from 'emacs -Q' yet, and also haven't caught it in a debugger unfortunately. The crash seems to happen somewhat reliably when I open a couple file buffers from one project, then open a new frame -> another buffer in another large project that has lots of files (which happens to also use `go-mode' and `lsp-mode'), and try running `helm-do-ag-project-root' while point is inside a symbol (which causes helm to pass a default to the minibuffer). I usually get a crash at this point. Sorry, I know that's not a lot of help (and unfortunately I can't share the contents of either of those projects that's triggering this). I'll try to get better reproduction steps and/or get a debugger backtrace if possible. --- In GNU Emacs 27.0.60 (build 1, x86_64-apple-darwin18.7.0, NS appkit-1671.60 Version 10.14.6 (Build 18G2022)) of 2020-01-10 built on jguenther-mbp Repository revision: ff8996a337377731905a7a3c9bf05e2281df40ef [NB: this is 16eaaa07e6ba6a41ccdc562dcb52fc87c38f8083 with the above patch applied] Repository branch: emacs-27 Windowing system distributor 'Apple', version 10.3.1671 System Description: Mac OS X 10.14.6 Configured using: 'configure --disable-silent-rules --enable-locallisppath=/usr/local/share/emacs/site-lisp --infodir=/usr/local/Cellar/emacs/27.0.60/share/info/emacs --prefix=/usr/local/Cellar/emacs/27.0.60 --with-gnutls --without-x --with-xml2 --with-dbus --with-imagemagick --with-modules --with-rsvg --with-json --with-ns --disable-ns-self-contained 'CFLAGS=-Os -w -pipe -march=nehalem -Xclang -target-feature -Xclang -aes -mmacosx-version-min=10.14 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk' 'CPPFLAGS=-I/usr/local/opt/icu4c/include -I/usr/local/opt/sqlite/include -I/usr/local/opt/readline/include -I/usr/local/opt/imagemagick@6/include -I/usr/local/opt/openssl@1.1/include -I/usr/local/opt/gettext/include -F/usr/local/Frameworks -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk' 'LDFLAGS=-L/usr/local/opt/icu4c/lib -L/usr/local/opt/sqlite/lib -L/usr/local/opt/readline/lib -L/usr/local/opt/imagemagick@6/lib -L/usr/local/opt/openssl@1.1/lib -L/usr/local/opt/libffi/lib -L/usr/local/opt/gettext/lib -L/usr/local/lib -F/usr/local/Frameworks -Wl,-headerpad_max_install_names -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk'' Configured features: RSVG IMAGEMAGICK DBUS GLIB NOTIFY KQUEUE ACL GNUTLS LIBXML2 ZLIB TOOLKIT_SCROLL_BARS NS MODULES THREADS JSON PDUMPER LCMS2 GMP Important settings: value of $EMACSDATA: /usr/local/opt/emacs/share/emacs/27.0.60/etc value of $EMACSDOC: /usr/local/opt/emacs/share/emacs/27.0.60/etc/ value of $EMACSLOADPATH: :/usr/local/opt/emacs/share/emacs/site-lisp:/usr/local/share/emacs/site-lisp/cask:/usr/local/opt/emacs/share/emacs/27.0.60/lisp:/usr/local/opt/emacs/share/emacs/27.0.60/site-lisp value of $EMACSPATH: /usr/local/opt/emacs/libexec/emacs/27.0.60/x86_64-apple-darwin18.7.0 value of $LC_ALL: en_CA.UTF-8 value of $LANG: en_CA.UTF-8 locale-coding-system: utf-8