On Fri, Apr 03, 2020 at 05:09:31PM +0700, Danh Doan wrote: > On 2020-04-03 10:22:54+0200, SZEDER Gábor <szeder.dev@xxxxxxxxx> wrote: > > On Thu, Apr 02, 2020 at 08:04:01PM +0700, Đoàn Trần Công Danh wrote: > > > We're using "su -m" to preserve environment variables in the shell run > > > by "su". But, that options will be ignored while "-l" (aka "--login") is > > > specified. > > > > This is not true. See any previous runs of the 32 bit Linux job, > > which worked as expected, because none of these environment variables > > were cleared. > > Different su have different behavior when combine "-m" and "-l" > > util-linux's su has this as far as 60541961f, (docs: improve grammar, > wording and formatting of su man page, 2013-10-12) > > -m, -p, --preserve-environment > Preserve the entire environment, i.e., it does not set HOME, > SHELL, USER nor LOGNAME. This option is ignored if the option > --login is specified. > > https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/tree/login-utils/su.1#n120 > > Ubuntu (our Linux32 builder), ships su by shadow-utils: > > Note that the default behavior for the environment is the following: > The $HOME, $SHELL, $USER, $LOGNAME, $PATH, > and $IFS environment variables are reset. > > If --login is not used, the environment is copied, > except for the variables above. > > If --login is used, the $TERM, $COLORTERM, $DISPLAY, and > $XAUTHORITY environment variables are copied if they were set. > > There're no mentions of other variables, I _think_ our Linux32 works > by accident. We do know which image we use, and we do know how its 'su' behaves. I think relying on that is fine, and it's not just "works by accident". > Alpine ships su from busybox, this su ignores "-m" if "-l" is set. Then the commit message should specifically mention these behavior differences between different 'su' variants.
