Currently, dmd/src/osmodel.mak uses the output of uname -m (if not already set) to determine the value of $(MODEL) which is used to determine if a 32 or 64 bit binary should be built. On Solarish systems (this includes Illumos based distos), this value isn't very useful. isainfo -n will output a value (amd64/i386) that is more suitable.
Commits pushed to master at https://github.com/D-Programming-Language/dmd https://github.com/D-Programming-Language/dmd/commit/6c5c5a9b0ee8bcec314867ad0d7121ff61b9b97c Fix issue 12962 - use isainfo on Solaris to determine model https://github.com/D-Programming-Language/dmd/commit/dd45b507315999e84eab46a4af251aace2bd420e Merge pull request #3686 from jasonbking/issue_12962 Fix issue 12962 - use isainfo on Solaris to determine model
Commit pushed to master at https://github.com/D-Programming-Language/druntime https://github.com/D-Programming-Language/druntime/commit/1b00a711ad2b810caf2da4c770b899df69890304 Fix issue 12962 - Should use isainfo on Solaris systems to determine model