Accelerator region ignored

I’m trying to compile some code with OpenACC directives. With an unoptimized build (-O0) I get

PGF90-W-0155-Accelerator region ignored; see -Minfo messages

I’m wondering what -Minfo messages is referring to. Is it telling me to look somewhere for more information?

Here is my compile line

/projects/opt/pgi/linux86-64/12.9/bin/pgfortran  -o CMakeFiles/chicoma.dir/comp_subs.f90.o  -Mpreprocess -Kieee -mp -Mcuda -ta=nvidia,cc20 -g -O0 -Mbounds -Ktrap=inv,divz,ovf,unf -I/home/mpi/openmpi/1.5.3-gcc-4.5.1-mar.16.11/include   -c /home/wohlbier/Chicoma/chicoma-hg/src/comp_subs.f90

Never mind, I figured it out. I set -Minfo=accel to see the relevant messages, and then saw that there was a subroutine inserted by -Mbounds that prevented the OpenACC directives from kicking in.