[bug #62397] jobserver unavailable from $(shell $(MAKE)...)

[Martin Dorey]

URL:
  <https://savannah.gnu.org/bugs/?62397>

                 Summary: jobserver unavailable from $(shell $(MAKE)...)
                 Project: make
            Submitted by: mdorey
            Submitted on: Mon 02 May 2022 05:42:45 PM PDT
                Severity: 3 - Normal
              Item Group: Bug
                  Status: None
                 Privacy: Public
             Assigned to: None
             Open/Closed: Open
         Discussion Lock: Any
       Component Version: SCM
        Operating System: POSIX-Based
           Fixed Release: None
           Triage Status: None

    _______________________________________________________

Details:

This warning:


make[1]: warning: jobserver unavailable: using -j1.  Add '+' to parent make
rule.


... in this demonstration, with a make pulled and built today:


martind@sirius:~/tmp/D150109$ ~/download/make/make --version
GNU Make 4.3.90
Built for x86_64-pc-linux-gnu
Copyright (C) 1988-2022 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
<https://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
martind@sirius:~/tmp/D150109$ cat Makefile 
default:; $(MAKE) -f 2.make
martind@sirius:~/tmp/D150109$ cat 2.make
OUTPUT := $(shell env | grep MAKEFLAGS 1>&2; $(MAKE) -f 3.make)
default:; @true
martind@sirius:~/tmp/D150109$ cat 3.make
default:; @true
martind@sirius:~/tmp/D150109$ ~/download/make/make -j2
/home/martind/download/make/make -f 2.make
make[1]: Entering directory '/home/martind/tmp/D150109'
MAKEFLAGS= -j2 --jobserver-auth=3,4
make[1]: warning: jobserver unavailable: using -j1.  Add '+' to parent make
rule.
make[1]: Leaving directory '/home/martind/tmp/D150109'
martind@sirius:~/tmp/D150109$ 


... is new with https://savannah.gnu.org/bugs/?58232 (FD_CLOEXEC not
initialized on jobserver pipe for recursive make invocations) or so says my
git bisect.  I wanted to use $(MAKE), so that the same Make program would be
used for nested invocations, as
https://www.gnu.org/software/make/manual/html_node/MAKE-Variable.html#MAKE-Variable
recommends.  I can get rid of the problem by emptying MAKEFLAGS, as suggested
by:

https://stackoverflow.com/questions/56485222/gnu-make-nested-calls

... eg like this:


martind@sirius:~/tmp/D150109$ cat 2.work-around 
OUTPUT := $(shell env | grep MAKEFLAGS 1>&2; MAKEFLAGS= $(MAKE) -f 3.make)
default:; @true
martind@sirius:~/tmp/D150109$ 


... and maybe that's not unreasonable because maybe I wouldn't want to pass on
eg -n to such (unusual) invocations.  That's what we've done in production to
support the Make from Debian Bullseye, which cherry picked that as-yet
unreleased fix.  Not passing the jobserver fds might be a more reasonable
choice than scraping the arguments to $(shell), looking for $(MAKE), but, in
that case, perhaps it would be better were Make not to pass MAKEFLAGS to
$(shell) invocations either.  Deciding it's not a bug is fine by me - I really
just wanted to make the issue and the work around better known.





    _______________________________________________________

Reply to this item at:

  <https://savannah.gnu.org/bugs/?62397>

_______________________________________________
  Message sent via Savannah
  https://savannah.gnu.org/