swanmain.f:(.text+0x0): multiple definition of `MAIN__'; /mnt/c/FYP/adcirc_v55.01/work/odir44/driver

[LIN2]

I encounter the problem like this:

ld: /mnt/c/FYP/adcirc_v55.01/work/odir44/swanmain.o: in function `MAIN__':
swanmain.f:(.text+0x0): multiple definition of `MAIN__'; /mnt/c/FYP/adcirc_v55.01/work/odir44/driver.o:driver.F:(.text+0x0): first defined here
make[1]: *** [makefile:605: padcswan] Error 1
make[1]: Leaving directory '/mnt/c/FYP/adcirc_v55.01/work'
make: *** [makefile:517: padcswan] Error 2

what should i do

[Arjen_Markus]

A program can only have one MAIN program unit. In Fortran that is the program unit. Apparently your link statement includes two or more object files that are derived from a source file containing "program somename"'. You will have to check which one is the correct one. (Or perhaps one should be a subroutine)

[mecej4]

The error messages from the linker make it quite clear that both swanmain.o and driver.o contain main program units. Only one of the two should be used. Which one? That is for you to determine, based on what the files contain and what you are attempting to build.

[Ron_Green]

If your main program is C calling a Fortran library or routine, you'll need -nofor-main 

HERE for details

and read the Developer Guide and Reference, Mixed Language programming, compiling and linking.