MIO_DEBUG

The purpose of the MIO_DEBUG environment variable is to aid in debugging MIO.

MIO searches MIO_DEFAULTS for keywords and provides debugging output for the option. The available keywords are:
ALL
Turns on all the MIO_DEBUG environment variable keywords.
ENV
Outputs environment variable matching requests.
OPEN
Outputs open requests made to the MIO_open64 subroutine.
MODULES
Outputs modules invoked for each call to the MIO_open64 subroutine.
TIMESTAMP
Places into a stats file a timestamp preceding each entry.
DEF
Outputs the definition table of each module. This dump is executed for all MIO library modules when the file opens.