Hi Chris, Did you have a chance to look into it?
https://issues.guix.gnu.org/53355 TIA. :-) Ludo’. Ludovic Courtès <l...@gnu.org> skribis: > Hi Chris, > > Thanks for debugging this! > > Chris Marusich <cmmarus...@gmail.com> skribis: > >> From c3eea81846ae71a246e6b592be74062f4bf26474 Mon Sep 17 00:00:00 2001 >> From: Chris Marusich <cmmarus...@gmail.com> >> Date: Sun, 13 Feb 2022 14:15:14 -0800 >> Subject: [PATCH] environment: Prevent PS1 from clobbering output in 'check'. >> >> Fixes: <https://issues.guix.gnu.org/51466>. >> >> * guix/scripts/environment.scm (child-shell-environment): In the script >> executed the child shell, set PS1 to an empty value and then echo three >> sentinel lines to try to "flush" the original PS1 value before printing the >> environment variables. In the parent process, read and discard all lines up >> to and including the last sentinel line. After that, read the remaining >> lines >> as usual. > > [...] > >> + ;; Why print "GUIX_FLUSH" a few times? We are trying to "flush" the >> + ;; original PS1 value to the port so we can read it (and discard it) >> + ;; before we start reading the environment variables from the port. If >> we >> + ;; don't do this, the original PS1 value can sometimes get interleaved >> + ;; into the output, which interferes with our parsing logic. It's a >> hack, >> + ;; but in practice it seems to do the job. If you know of a more >> graceful >> + ;; solution, please implement it! See: >> https://issues.guix.gnu.org/51466 >> + "PS1=; for i in 1 2 3; do echo GUIX_FLUSH_$i; done; \ >> +env || /usr/bin/env || set; echo GUIX-CHECK-DONE; read x; exit\n") > > So you confirm that a single “echo” is not enough, right? > > Perhaps we should unroll the ‘for’ loop for portability, to be on the > safe side. Initially I tested with Bash, Zsh, and Fish: > > https://issues.guix.gnu.org/51285#0-lineno49 > > I think Fish has a very non-POSIX syntax, hence the suggestion to avoid > ‘for’. > > I realized that setting PS1 could interfere with the logic below that > checks for PS1. And since it doesn’t seem to help, perhaps we can > remove “PS1=;”? > > Thoughts? > > Sorry to answer with yet more questions! > > Thanks, > Ludo’.