https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123366
--- Comment #14 from Dimitry Andric <dimitry at andric dot com> ---
Difference between "good" and "bad" builds seem to mainly in the resulting
CXXFLAGS and LDFLAGS for gcc/Makefile:
The "good" builds have CXXFLAGS=-g -O2 -fchecking=1 and
LDFLAGS=-static-libstdc++ -static-libgcc, while the "bad" builds have empty
CXXFLAGS and LDFLAGS.
Diff of the interesting files of the work directories (good first, bad second):
--- /wrkdirs/share/dim/ports/lang/gcc16-devel/work.good/.build/gcc/Makefile
2026-01-09 18:42:41.163059000 +0100
+++ /wrkdirs/share/dim/ports/lang/gcc16-devel/work.bad/.build/gcc/Makefile
2026-01-09 19:17:11.799097000 +0100
@@ -153,8 +153,8 @@ CFLAGS = -g -O2 -fchecking=1
TCFLAGS =
TFLAGS =
CFLAGS = -g -O2 -fchecking=1
-CXXFLAGS = -g -O2 -fchecking=1
-LDFLAGS = -static-libstdc++ -static-libgcc
+CXXFLAGS =
+LDFLAGS =
# Should we build position-independent host code?
PICFLAG = -fPIC
@@ -425,7 +425,7 @@ PLUGINCC = /wrkdirs/share/dim/ports/lang/gcc16-devel/
# Compiler and flags needed for plugin support
PLUGINCC =
/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/./prev-gcc/xg++
-B/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/./prev-gcc/
-B/usr/local/x86_64-portbld-freebsd16.0/bin/ -nostdinc++
-B/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/src/.libs
-B/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/libsupc++/.libs
-isystem
/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/include/x86_64-portbld-freebsd16.0
-isystem
/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/include
-isystem
/wrkdirs/share/dim/ports/lang/gcc16-devel/work/gcc-16-20251130/libstdc++-v3/libsupc++
-L/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/src/.libs
-L/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/libsupc++/.libs
-PLUGINCFLAGS = -g -O2 -fchecking=1
+PLUGINCFLAGS =
# Libs and linker options needed for plugin support
PLUGINLIBS = -rdynamic
diff -uprd -I ^configure:[0-9]*: -I /home/dim/tmp/cc.*\.o -I
/home/dim/tmp/conftest-.*\.o
/wrkdirs/share/dim/ports/lang/gcc16-devel/work.good/.build/gcc/config.log
/wrkdirs/share/dim/ports/lang/gcc16-devel/work.bad/.build/gcc/config.log
--- /wrkdirs/share/dim/ports/lang/gcc16-devel/work.good/.build/gcc/config.log
2026-01-09 18:42:41.278156000 +0100
+++ /wrkdirs/share/dim/ports/lang/gcc16-devel/work.bad/.build/gcc/config.log
2026-01-09 19:17:11.947281000 +0100
@@ -10014,7 +10014,7 @@ CXXDEPMODE='depmode=gcc3'
CXX=' /wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/./prev-gcc/xg++
-B/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/./prev-gcc/
-B/usr/local/x86_64-portbld-freebsd16.0/bin/ -nostdinc++
-B/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/src/.libs
-B/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/libsupc++/.libs
-isystem
/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/include/x86_64-portbld-freebsd16.0
-isystem
/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/include
-isystem
/wrkdirs/share/dim/ports/lang/gcc16-devel/work/gcc-16-20251130/libstdc++-v3/libsupc++
-L/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/src/.libs
-L/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/libsupc++/.libs'
CXXCPP=' /wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/./prev-gcc/xg++
-B/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/./prev-gcc/
-B/usr/local/x86_64-portbld-freebsd16.0/bin/ -nostdinc++
-B/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/src/.libs
-B/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/libsupc++/.libs
-isystem
/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/include/x86_64-portbld-freebsd16.0
-isystem
/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/include
-isystem
/wrkdirs/share/dim/ports/lang/gcc16-devel/work/gcc-16-20251130/libstdc++-v3/libsupc++
-L/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/src/.libs
-L/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/libsupc++/.libs
-E'
CXXDEPMODE='depmode=gcc3'
-CXXFLAGS='-g -O2 -fchecking=1'
+CXXFLAGS=''
CXX_FOR_BUILD='$(CXX)'
DATADIRNAME=''
DEFAULT_INSNEMIT_PARTITIONS='10'
@@ -10064,7 +10064,7 @@ LDEXP_LIB=''
ISLLIBS=''
LD='/usr/local/bin/ld'
LDEXP_LIB=''
-LDFLAGS='-static-libstdc++ -static-libgcc '
+LDFLAGS=''
LD_PICFLAG='-no-pie'
LIBGDIAGNOSTICS=''
LIBICONV=''
diff -uprd -I ^configure:[0-9]*: -I /home/dim/tmp/cc.*\.o -I
/home/dim/tmp/conftest-.*\.o
/wrkdirs/share/dim/ports/lang/gcc16-devel/work.good/.build/gcc/config.status
/wrkdirs/share/dim/ports/lang/gcc16-devel/work.bad/.build/gcc/config.status
---
/wrkdirs/share/dim/ports/lang/gcc16-devel/work.good/.build/gcc/config.status
2026-01-09 18:42:41.111314000 +0100
+++ /wrkdirs/share/dim/ports/lang/gcc16-devel/work.bad/.build/gcc/config.status
2026-01-09 19:17:11.733896000 +0100
@@ -1013,7 +1013,7 @@ S["ac_ct_CXX"]=""
S["GNATMAKE"]="no"
S["GNATBIND"]="/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/./prev-gcc/gnatbind"
S["ac_ct_CXX"]=""
-S["CXXFLAGS"]="-g -O2 -fchecking=1"
+S["CXXFLAGS"]=""
S["CXX"]="
/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/./prev-gcc/xg++
-B/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/./prev-gcc/ -B/usr/lo"\
"cal/x86_64-portbld-freebsd16.0/bin/ -nostdinc++
-B/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3"\
"/src/.libs
-B/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/prev-x86_64-portbld-freebsd16.0/libstdc++-v3/libsupc++/.libs
-isystem /wrkdirs/s"\
@@ -1025,7 +1025,7 @@ S["CPPFLAGS"]="-DLIBICONV_PLUG"
S["EXEEXT"]=""
S["ac_ct_CC"]=""
S["CPPFLAGS"]="-DLIBICONV_PLUG"
-S["LDFLAGS"]="-static-libstdc++ -static-libgcc "
+S["LDFLAGS"]=""
S["CFLAGS"]="-g -O2 -fchecking=1"
S["CC"]="
/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/./prev-gcc/xgcc
-B/wrkdirs/share/dim/ports/lang/gcc16-devel/work/.build/./prev-gcc/ -B/usr/lo"\
"cal/x86_64-portbld-freebsd16.0/bin/
-B/usr/local/x86_64-portbld-freebsd16.0/bin/
-B/usr/local/x86_64-portbld-freebsd16.0/lib/ -isystem /usr/local/x8"\
