Compilation Error

[iris]

Hello, I have got this error when I tried to install Delphes in MG5

gcc: error: unrecognized command line option ‘-stdlib=libc++’
gcc: error: unrecognized command line option ‘-stdlib=libc++’
make: * [tmp/external/tcl/tclObj.o] Error 1
Error detected during the compilation. Please check the compilation error and run make manually.

Are there any solutions to this? Thank you very much!!!

[Pavel Demin]

This problem was already discussed in

https://cp3.irmp.ucl.ac.be/projects/delphes/ticket/315

and it's fixed in the latest Delphes release.

MadGraph is using previous version of Delphes where this problems is still present.

Could you try to replace the following line in Delphes/Makefile

@gcc $(CXXFLAGS) -c $< $(OutPutOpt)$@

with the following expression

@$(CC) $(patsubst -std=%,,$(CXXFLAGS)) -c $< $(OutPutOpt)$@

The commands to build Delphes are:

cd Delphes
make

[iris]

I have changed the line as you said and build.

When I tried to install Delphes in MadGraph, the compilation error remained. And the Delphes/Makefile was automatically changed back to the original version( i.e. the line

@$(CC) $(patsubst -std=%,,$(CXXFLAGS)) -c $< $(OutPutOpt)$@

changed back to

@gcc $(CXXFLAGS) -c $< $(OutPutOpt)$@

I don't know why.

[Pavel Demin]

Once you change Makefile, you have to rebuild Delphes manually. I thought that MadGraph will automatically recognize this manually rebuilt Delphes installation.

I've just modified Makefile in the .tar.gz file that MadGraph downloads.

Could you try to reinstall Delphes in MadGraph?

[iris]

Succeeded! Thank you very much!