When using the Absoft 2019 compilers on Windows and Linux, if one or more module files (*.mod) exist in the current working directory, and those were produced by an earlier compilation with Gfortran, attempting to compile a Fortran source file in the same directory using the Absoft compiler causes the compiler to hang.
To demonstrate the bug, use the source code below. Compile using gfortran -c. A MOD file is produced. Leave it alone. Then, attempt to compile the same source file using Absoft Fortran. The compiler hangs. Even the presence of an unrelated MOD file that was produced by Gfortran causes the Absoft Fortran compiler to hang.
module xy
implicit none
integer :: xyz = 2
end module xy
The impression I have is that the compiler may be attempting to read any existing MOD files in the current directory, even if no USE statements name those modules in the source file being compiled.
I used Gfortran 7.2, but I don't think that the Gfortran version matters much.
P.S.:
When I posted the bug report yesterday, I had used Absoft 2019 on (i) OpenSuse Linux Leap 15 X64, and (ii) Windows 10 X64. Today, I found that the problem can be reproduced on Windows 10 X64 (different PC) with Absoft 14.0.6 and Gfortran 6.1. Perhaps the problem exists with Gfortran-generated MOD files because these files are Gzip-compressed text files.
I also tested with .MOD files produced by Lahey LF95 on Windows 10, and then no problems were seen.
P.P.S:
While collecting the information presented above, I observed a different issue: For the test source code given above, other compilers produced MOD files that were one or two hundred bytes long. Absoft Fortran generated a 120+ kbyte MOD file. This property of Absoft Fortran may cause space and time problems during compilations of large projects with many modules and source files, because each USE statement may require many large module files to be read and digested by the compiler.
For your convenience, I have attached the MOD file produced by Gfortran 6.3 on Windows 10 / Cygwin 64.