ExitCode consistency

Haskell 98 says

Computation system cmd returns the exit code produced when the operating system processes the command cmd.

and

The exact interpretation of code is operating-system dependent.

However, on Unix systems system "exit 3" >>= print prints ExitFailure 3 under ghc and hugs, but ExitFailure 768 under nhc98, despite both being the same operating system.

It may not be possible to fix this within the boundaries of the report, but Something Must Be Done somewhere.

Additionally, the report says

The value exitFailure is equal to exitWith (ExitFailure exitfail), where exitfail is implementation-dependent.

while operating-system dependent seems better than implementation-dependent.

Trac metadata

Trac field	Value
Version
Type	Task
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	HaskellPrime
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture

changed weight to 5

added Trac import task labels

assigned to @trac-none and unassigned @trac-ijones

Trac metadata

Trac field	Value
Component	HaskellPrime → Proposal

changed milestone to %⊥

moving non-milestoned many year old legacy tickets out of the way

Set default priority (as this confuses Trac otherwise)