Matlab mex error for gcc 13 on Ubuntu 24

[barrackHa]

Compiling READCXDATA from source throws an error on:

OS: Ubuntu 24.4
MATLAB R2025b
gcc (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0
Maestro 5.2
Readcxdata 5.2

Error is:

'''

mex -v readcxdata.c pertmgr.c noisyem.c
Verbose mode is on.
... Looking for compiler 'gcc' ...
... Executing command 'which gcc' ...Yes ('/usr/bin/gcc').
... Executing command 'gcc -dumpversion' ...Yes ('13').
... Executing command 'gcc -print-file-name=libstdc++.so' ...Yes ('/usr/lib/gcc/x86_64-linux-gnu/13/libstdc++.so').
Found installed compiler 'gcc'.
Options file details

---

Compiler location: /usr/bin/gcc
Options file: ~/.matlab/R2025b/mex_C_glnxa64.xml
CMDLINE2 : /usr/bin/gcc -pthread -Wl,--no-undefined -Wl,-rpath-link,/usr/local/MATLAB/R2025b/bin/glnxa64 -shared  -O -Wl,--version-script,"/usr/local/MATLAB/R2025b/extern/lib/glnxa64/c_exportsmexfileversion.map" /tmp/mex_1665375375591384_930929/readcxdata.o /tmp/mex_1665375375591384_930929/pertmgr.o /tmp/mex_1665375375591384_930929/noisyem.o /tmp/mex_1665375375591384_930929/c_mexapi_version.o   -L"/usr/local/MATLAB/R2025b/bin/glnxa64" -lmx -lmex -lmat -lm -lstdc++ -z noexecstack -o readcxdata.mexa64
CC : /usr/bin/gcc
DEFINES : -DMATLAB_DEFAULT_RELEASE=R2017b  -DUSE_MEX_CMD   -D_GNU_SOURCE -DMATLAB_MEX_FILE 
MATLABMEX : -DMATLAB_MEX_FILE 
CFLAGS : -fexceptions -fPIC -fno-omit-frame-pointer -pthread -fwrapv
INCLUDE : -I"/usr/local/MATLAB/R2025b/extern/include" -I"/usr/local/MATLAB/R2025b/simulink/include"
COPTIMFLAGS : -O2 -DNDEBUG -fno-predictive-commoning
CDEBUGFLAGS : -g
LD : /usr/bin/gcc
LDFLAGS : -pthread -Wl,--no-undefined -Wl,-rpath-link,/usr/local/MATLAB/R2025b/bin/glnxa64
LDTYPE : -shared 
FUNCTIONMAP : "/usr/local/MATLAB/R2025b/extern/lib/glnxa64/mexFunction.map"
VERSIONMAP : "/usr/local/MATLAB/R2025b/extern/lib/glnxa64/c_exportsmexfileversion.map"
LINKEXPORT : -Wl,--version-script,"/usr/local/MATLAB/R2025b/extern/lib/glnxa64/mexFunction.map"
LINKEXPORTVER : -Wl,--version-script,"/usr/local/MATLAB/R2025b/extern/lib/glnxa64/c_exportsmexfileversion.map"
LINKLIBS : -L"/usr/local/MATLAB/R2025b/bin/glnxa64" -lmx -lmex -lmat -lm -lstdc++
LDOPTIMFLAGS : -O
LDDEBUGFLAGS : -g
MWCPPLIB : "/usr/local/MATLAB/R2025b/sys/os/glnxa64/orig/libstdc++.so.6"
LDEXECSTACK : -z noexecstack
OBJEXT : .o
LDEXT : .mexa64
SETENV : CC="/usr/bin/gcc"
            CXX="g++"
            CFLAGS="-fexceptions -fPIC -fno-omit-frame-pointer -pthread -fwrapv -DMATLAB_DEFAULT_RELEASE=R2017b  -DUSE_MEX_CMD   -D_GNU_SOURCE -DMATLAB_MEX_FILE "
            CXXFLAGS="-fexceptions -fPIC -fno-omit-frame-pointer -pthread -fwrapv -DMATLAB_DEFAULT_RELEASE=R2017b  -DUSE_MEX_CMD   -D_GNU_SOURCE -DMATLAB_MEX_FILE "
            COPTIMFLAGS="-O2 -DNDEBUG -fno-predictive-commoning"
            CXXOPTIMFLAGS="-O2 -DNDEBUG -fno-predictive-commoning"
            CDEBUGFLAGS="-g"
            CXXDEBUGFLAGS="-g"                
            MW_GLIBC_SHIM="$MW_GLIBC_SHIM"
            LD="/usr/bin/gcc"
            LDXX="g++"
            LDFLAGS="-pthread -Wl,--no-undefined -Wl,-rpath-link,/usr/local/MATLAB/R2025b/bin/glnxa64 -shared  -L"/usr/local/MATLAB/R2025b/bin/glnxa64" -lmx -lmex -lmat -lm -lstdc++ -Wl,--version-script,"/usr/local/MATLAB/R2025b/extern/lib/glnxa64/mexFunction.map""
            LDDEBUGFLAGS="-g"
GCC : /usr/bin/gcc
VER : 13
CPPLIBS : /usr/lib/gcc/x86_64-linux-gnu/13/libstdc++.so
MATLABROOT : /usr/local/MATLAB/R2025b
ARCH : glnxa64
SRC : "/home/barak/Documents/MATLAB/cxdata_src_V502/readcxdata.c";"~/Documents/MATLAB/cxdata_src_V502/pertmgr.c";"~/Documents/MATLAB/cxdata_src_V502/noisyem.c";"/usr/local/MATLAB/R2025b/extern/version/c_mexapi_version.c"
OBJ : /tmp/mex_1665375375591384_930929/readcxdata.o;/tmp/mex_1665375375591384_930929/pertmgr.o;/tmp/mex_1665375375591384_930929/noisyem.o;/tmp/mex_1665375375591384_930929/c_mexapi_version.o
OBJS : /tmp/mex_1665375375591384_930929/readcxdata.o /tmp/mex_1665375375591384_930929/pertmgr.o /tmp/mex_1665375375591384_930929/noisyem.o /tmp/mex_1665375375591384_930929/c_mexapi_version.o 
SRCROOT : ~/Documents/MATLAB/cxdata_src_V502/readcxdata
DEF : /tmp/mex_1665375375591384_930929/readcxdata.def
EXP : "readcxdata.exp"
LIB : "readcxdata.lib"
EXE : readcxdata.mexa64
ILK : "readcxdata.ilk"
TEMPNAME : readcxdata
EXEDIR : 
EXENAME : readcxdata
MANIFEST : "readcxdata.mexa64.manifest"
OPTIM : -O2 -DNDEBUG -fno-predictive-commoning
LINKOPTIM : -O
CMDLINE1_0 : /usr/bin/gcc -c -DMATLAB_DEFAULT_RELEASE=R2017b  -DUSE_MEX_CMD   -D_GNU_SOURCE -DMATLAB_MEX_FILE  -I"/usr/local/MATLAB/R2025b/extern/include" -I"/usr/local/MATLAB/R2025b/simulink/include" -fexceptions -fPIC -fno-omit-frame-pointer -pthread -fwrapv -O2 -DNDEBUG -fno-predictive-commoning "/home/barak/Documents/MATLAB/cxdata_src_V502/readcxdata.c" -o /tmp/mex_1665375375591384_930929/readcxdata.o
CMDLINE1_1 : /usr/bin/gcc -c -DMATLAB_DEFAULT_RELEASE=R2017b  -DUSE_MEX_CMD   -D_GNU_SOURCE -DMATLAB_MEX_FILE  -I"/usr/local/MATLAB/R2025b/extern/include" -I"/usr/local/MATLAB/R2025b/simulink/include" -fexceptions -fPIC -fno-omit-frame-pointer -pthread -fwrapv -O2 -DNDEBUG -fno-predictive-commoning "/home/barak/Documents/MATLAB/cxdata_src_V502/pertmgr.c" -o /tmp/mex_1665375375591384_930929/pertmgr.o
CMDLINE1_2 : /usr/bin/gcc -c -DMATLAB_DEFAULT_RELEASE=R2017b  -DUSE_MEX_CMD   -D_GNU_SOURCE -DMATLAB_MEX_FILE  -I"/usr/local/MATLAB/R2025b/extern/include" -I"/usr/local/MATLAB/R2025b/simulink/include" -fexceptions -fPIC -fno-omit-frame-pointer -pthread -fwrapv -O2 -DNDEBUG -fno-predictive-commoning "/home/barak/Documents/MATLAB/cxdata_src_V502/noisyem.c" -o /tmp/mex_1665375375591384_930929/noisyem.o
CMDLINE1_3 : /usr/bin/gcc -c -DMATLAB_DEFAULT_RELEASE=R2017b  -DUSE_MEX_CMD   -D_GNU_SOURCE -DMATLAB_MEX_FILE  -I"/usr/local/MATLAB/R2025b/extern/include" -I"/usr/local/MATLAB/R2025b/simulink/include" -fexceptions -fPIC -fno-omit-frame-pointer -pthread -fwrapv -O2 -DNDEBUG -fno-predictive-commoning "/usr/local/MATLAB/R2025b/extern/version/c_mexapi_version.c" -o /tmp/mex_1665375375591384_930929/c_mexapi_version.o

---

Building with 'gcc'.
/usr/bin/gcc -c -DMATLAB_DEFAULT_RELEASE=R2017b -DUSE_MEX_CMD -D_GNU_SOURCE -DMATLAB_MEX_FILE -I"/usr/local/MATLAB/R2025b/extern/include" -I"/usr/local/MATLAB/R2025b/simulink/include" -fexceptions -fPIC -fno-omit-frame-pointer -pthread -fwrapv -O2 -DNDEBUG -fno-predictive-commoning "/home/barak/Documents/MATLAB/cxdata_src_V502/readcxdata.c" -o /tmp/mex_1665375375591384_930929/readcxdata.o
Error using mex
In file included from /home/barak/Documents/MATLAB/cxdata_src_V502/readcxdata.h:16,
from /home/barak/Documents/MATLAB/cxdata_src_V502/readcxdata.c:216:
~/Documents/MATLAB/cxdata_src_V502/cxfilefmt_mex.h:606:21: error: variably
modified �tgtsV24� at file scope
606 | CXFILETGT_V24 tgtsV24[CX_RECORDTARGETS_V24]; // for
CX_TGTRECORD, v = [23..24]
| ^~~~~~~
'''

[barrackHa]

The fix to this issue is in this PR.