Re: [lmi] Mounting proc and devpts for chroot [Was: Using Git submodules for the dependencies]

[Greg Chicares]

On 2019-09-24 00:24, Vadim Zeitlin wrote:
> On Tue, 24 Sep 2019 00:00:53 +0000 Greg Chicares <address@hidden> wrote:
[...information about linux systems...]> can usually be found on the web, or 
even in
> the kernel documentation itself, but usually you know what to look for in
> order to find it, which is definitely inconvenient.

Indeed: e.g., "char 5,2 device" makes sense now that I look here:

  https://linux.die.net/man/4/ptmx
| The file /dev/ptmx is a character file with major number 5 and minor number 2

but first I had to know to look for "ptmx".

> GC> [...] the redirections in
> GC> lmi's unit-test suite:
> GC> 
> GC> make "$coefficiency" --output-sync=recurse unit_tests 2>&1 \
> GC>   | tee >(grep '\*\*\*') >(grep \?\?\?\?) >(grep '!!!!' --count | xargs 
> printf '%d tests succeeded\n') >"$log_dir"/unit_tests
> GC> 
> GC> seem to fail without PTYs.

Correction--what I had observed was this:
  tee: /proc/self/fd/14: No such file or directory
I no longer see that, now that I've mounted
  devpts /srv/chroot/bullseye0/dev/pts devpts 
rw,nosuid,noexec,relatime,mode=600,ptmxmode=000 0 0
  proc   /srv/chroot/bullseye0/proc    proc   rw,nosuid,nodev,noexec,relatime 0 0
for the chroot, but that's because of proc, not devpts.

Maybe devpts isn't actually used by the lmi build scripts.
It doesn't seem to be required for the process substitutions
in this unit-test command, as seen below.

>  Running this prefixed with "ltrace -f -e openpty --" should show if
> anything here uses pseudo-terminals (provided ltrace is installed, of
> course), but I'm not curious or wakeful enough to do it right now.

/opt/lmi/src/lmi[0]$ltrace -f -e openpty -- make $coefficiency 
--output-sync=recurse unit_tests build_type=safestdlib 2>&1 | tee >(grep 
'\*\*\*') >(grep '????') >(grep '!!!!' --count | xargs printf '%d tests 
succeeded\n') >../log

/opt/lmi/src/lmi[0]$<../log sed -e'/^[[]pid/!d' -e'/+++ exited (status [0-9]) 
+++/d' -e'/--- Called exec() ---/d' -e'/--- SIGCHLD (Child exited) ---/d'      
[pid 32031] --- SIGQUIT (Quit) ---
[pid 32036] --- SIGQUIT (Quit) ---
[pid 32011] --- SIGUSR1 (User defined signal 1) ---
[pid 32080] --- SIGQUIT (Quit) ---
[pid 32056] --- SIGUSR1 (User defined signal 1) ---
[pid 32126] --- SIGQUIT (Quit) ---
[pid 32102] --- SIGUSR1 (User defined signal 1) ---
[pid 32758] --- SIGQUIT (Quit) ---
[pid 32734] --- SIGUSR1 (User defined signal 1) ---
/opt/lmi/src/lmi[0]$