build.sh -V MKDEBUGLIB=yes fails with: wg_user.c:45:10: fatal error: assert.h: No such file or directory

Hello!

When I try distribution build (CURRENT, Jul 5, 2026) with Debug 
libraries (MKDEBUGLIB=yes) I encounter build error:

cd /usr/src
./build.sh -O ../obj -T ../tools -j 1C -x -U -V MKDEBUGLIB=yes distribution

...
/usr/src/sys/rump/net/lib/libwg/wg_user.c:45:10: fatal error: assert.h: 
No such file or directory
    45 | #include <assert.h> 

       |          ^~~~~~~~~~ 
                                                 compilation terminated. 
  

  

*** Failed target: wg_user.go 

*** In directory: /usr/src/sys/rump/net/lib/libwg 

*** Failed commands: 

         ${_MKTARGET_COMPILE} 

         => @echo '#  ' "compile " libwg/wg_user.go
         ${COMPILE.c} ${DEBUGFLAGS} ${COPTS.${.IMPSRC:T}} 
${CPUFLAGS.${.IMPSRC:T}} ${CPPFLAGS.${.IMPSRC:T}} -g ${.IMPSRC}
  -o ${.TARGET}
         => /usr/src/../tools/bin/x86_64--netbsd-gcc -O2 
-fno-delete-null-pointer-checks  -ffreestanding -fno-strict-ali
asing -mno-red-zone -mno-mmx -mno-sse -mno-avx -msoft-float   -std=gnu11 
    -Wall -Wstrict-prototypes -Wmissing-prototyp
es -Wpointer-arith -Wno-sign-compare  -Wsystem-headers 
-Wno-traditional   -Wa,--fatal-warnings  -Wreturn-type -Wswitch
  -Wshadow -Wcast-qual -Wwrite-strings -Wextra -Wno-unused-parameter 
-Wno-sign-compare -Werror    -Wno-address-of-packed-
member  -Wno-format-zero-length -Wno-pointer-sign   -fPIE 
-fstack-protector -Wstack-protector   --param ssp-buffer-siz
e=1    --sysroot=/usr/src/../obj/destdir.amd64 -DCOMPAT_50 -DCOMPAT_60 
-DCOMPAT_70 -DCOMPAT_80 -DCOMPAT_90 -DCOMPAT_100
-DCOMPAT_110 -nostdinc -I/usr/src/sys/rump/net/lib/libwg -I. 
-I/usr/src/sys/rump/net/lib/libwg/../../../../../common/inc
lude -I/usr/src/sys/rump/net/lib/libwg/../../../include 
-I/usr/src/sys/rump/net/lib/libwg/../../../include/opt -I/usr/sr
c/sys/rump/net/lib/libwg/../../../../arch 
-I/usr/src/sys/rump/net/lib/libwg/../../../.. -DDIAGNOSTIC -DKTRACE 
-imacros
/usr/src/sys/rump/net/lib/libwg/../../../include/opt/opt_rumpkernel.h 
-D_FORTIFY_SOURCE=2 -c -DDEBUG    -g /usr/src/sys
/rump/net/lib/libwg/wg_user.c -o wg_user.go 

*** [wg_user.go] Error code 1 

  

nbmake[7]: stopped making "realall" in /usr/src/sys/rump/net/lib/libwg 



CVS info:
cvs status sys/rump/net/lib/libwg/wg_user.c
===================================================================
File: wg_user.c         Status: Up-to-date

    Working revision:    1.5
    Repository revision: 1.5 
/cvsroot/src/sys/rump/net/lib/libwg/wg_user.c,v
    Commit Identifier:   SnsxfpV09iD53oMG
    Sticky Tag:          (none)
    Sticky Date:         (none)
    Sticky Options:      (none)


System info:
$ uname -a
NetBSD nbsd-head.example.com 11.99.6 NetBSD 11.99.6 (GENERIC) #0: Sun 
Jul  5 02:47:16 UTC 2026 
[email protected]:/usr/src/sys/arch/amd64/compile/GENERIC amd64

Building without MKDEBUGLIB=yes works fine.

Questions: Is this known problem? Anybody else can reproduce that?

Regards
  --Henryk Paluch