DrNim build fails due to missing -lpthread

[lainy]

Building DrNim from devel and version-1-4 branches fails on Debian Buster and Arch Linux (did not test others).

Example

$ ./koch drnim

Current Output

Full link stage output (Debian Buster):

$ ./koch drnim
-- snipped a couple thousand lines for brevity --
Hint:  [Link]
/usr/bin/ld: dist/z3/build/libz3.a(scoped_timer.cpp.o): undefined reference to symbol 'pthread_create@@GLIBC_2.2.5'
/usr/bin/ld: //lib/x86_64-linux-gnu/libpthread.so.0: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
Error: execution of an external program failed: 'g++   -o /home/lain/Nim/bin/drnim  /home/lain/.cache/nim/drnim_d/stdlib_assertions.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_dollars.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_formatfloat.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_io.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_system.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_parseutils.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_math.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_algorithm.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_unicode.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_strutils.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_pathnorm.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_posix.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_times.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_os.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_parseopt.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_hashes.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_tables.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_packedsets.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@spathutils.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sropes.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@slineinfos.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_strtabs.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_sets.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@splatform.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sprefixmatches.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_strformat.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_terminal.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@soptions.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@swordrecg.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sidents.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sint128.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sast.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@srodutils.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sstrutils2.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@smsgs.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sastalgo.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@strees.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sllstream.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@snimlexbase.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@slexer.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@srenderer.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@stypes.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@scondsyms.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_streams.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_osproc.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_sha1.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_lexbase.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_parsejson.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_json.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sextccomp.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@snimblecmd.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sincremental.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@scommands.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sbtrees.nim.cpp.o /home/lain/.cache/nim/drnim_d/stdlib_md5.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@smodulegraphs.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@smagicsys.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sbitsets.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@snimsets.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@ssaturate.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sguards.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sparser.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sfilters.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sfilter_tmpl.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@ssyntaxes.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@smodulepaths.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sreorder.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@spasses.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@smodules.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@ssemfold.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@svmdef.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@ssemdata.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@slinter.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@snimfix@sprettybase.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@slookups.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@ssemtypinst.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sparampatterns.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@slowerings.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@ssigmatch.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@simporter.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sprocfind.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@spragmas.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@stypeallowed.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sisolation_check.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@svarpartitions.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@ssighashes.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sliftdestructors.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@ssempass2.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@scgmeth.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sliftlocals.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@slambdalifting.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sclosureiters.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@stransf.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@svmgen.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@svmdeps.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@svmmarshal.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sgorgeimpl.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@smacrocacheimpl.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@svmprofiler.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sevaltempl.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@svmconv.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@svm.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@saliases.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@spatterns.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@ssemmacrosanity.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@spluginsupport.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@splugins@slocals.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@splugins@sitersgen.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@splugins@sactive.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sspawn.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@ssem.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@sscriptconfig.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@snimconf.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@scmdlinehelper.nim.cpp.o /home/lain/.cache/nim/drnim_d/@m..@scompiler@spassaux.nim.cpp.o /home/lain/.cache/nim/drnim_d/@mdrnim.nim.cpp.o  -lm -lm -lrt dist/z3/build/libz3.a   -ldl'
FAILURE

Note the same error occurs on Arch Linux as well.

Expected Output

The build should succeed.

Possible Solution

Adding -lpthread to the link arguments solves this.

Additional Information

Tested on Arch Linux and Debian Buster, both installed a few hours before filing this issue.
Tested on the following Nim versions:

$ nim -v
Nim Compiler Version 1.5.1 [Linux: amd64]
Compiled at 2020-11-19
Copyright (c) 2006-2020 by Andreas Rumpf

git hash: 1bcc3521371ec6a8c136e42d902a0be7c50d9745
active boot switches: -d:release

$ nim -v
Nim Compiler Version 1.4.0 [Linux: amd64]
Compiled at 2020-10-18
Copyright (c) 2006-2020 by Andreas Rumpf

git hash: bdcd87afca238a0a7b2c70971827cf9172817b12
active boot switches: -d:release

[ringabout]

Threads are now the default, it should not happen now.