Powellsr/fix/debug attach handling

[powellsr]

Mostly followed MPQC version, didn't use HAVE_SYSTEM macro, as it doesn't appear to be defined in TA code.
system_retvalue, ~ bug.cpp:240 may not be used correctly in MPQC. It's defined as zero and never changed; the system call return value is assigned to another var, which is cast to void (which I learned silences compiler warnings, is there a reason for this?

[evaleev]

Mostly followed MPQC version, didn't use HAVE_SYSTEM macro, as it doesn't appear to be defined in TA code.

HAVE_SYSTEM is no longer needed since std::system is standard.

system_retvalue, ~ bug.cpp:240 may not be used correctly in MPQC. It's defined as zero and never changed; the system call return value is assigned to another var, which is cast to void (which I learned silences compiler warnings, is there a reason for this?

Not sure which code you are looking at, this looks legit: https://github.com/ValeevGroup/mpqc4/blob/master/src/mpqc/util/misc/bug.cpp#L266

[powellsr]

Right, we'd fixed that, maybe the commit ended up in another branch, but that was an issue we handled in a meeting at some point