Haiku is an operation system different from Windows, Linux or *BSD. Still,
in many respects it can be considered Unix-like, which is especially true
when porting software to it.
CLISP was recently ported to Haiku. In the *features*, CLISP on Haiku
defines both :UNIX (i.e. Unix-like) and :HAIKU, and this is probably the
right decision. However, after (require "asdf"), *features* are changed,
:HAIKU is removed and :OS-UNIX is added. This is certainly something which
needs to be fixed. The desired solution would be to keep both :UNIX, :HAIKU
and to add :OS-HAIKU.
Here is the analysis from CLISP development list:
```
(defun detect-os ()
"Detects the current operating system. Only needs be run at
compile-time, except on ABCL where it might change between FASL compilation
and runtime."
(loop* :with o
:for (feature . detect) :in '((:os-unix . os-unix-p) (:os-macosx
. os-macosx-p) …
(:haiku . os-haiku-p))
:when (and (or (not o) (eq feature :os-macosx)) (funcall detect))
:do (setf o feature) (pushnew feature *features*)
:else :do (setf *features* (remove feature *features*))
:finally
(return (or o (error "Congratulations for trying ASDF on an
operating system~%~ that is neither Unix, nor Windows, nor Genera, nor even
old MacOS.~%Now you port it.")))))
That is somewhat brittle code that side-effects *FEATURES*. It contains a
special bypass to allow :OS-MACOSX to live there beside :OS-UNIX, but
there’s nothing equivalent for Haiku. Whether Haiku is considered a UNIX or
not I won’t debate.
I call such code /brittle/ because there’s an undocumented (non-explicitly
mentioned) dependency on element order in some innocuous list: If
:os-macosx were before :os-unix in the A-list, that code would not set –
and rather delete – :OS-UNIX in *features*.
I would have appreciated a tiny comment like
:for (feature . detect) :in '(…
(:os-unix . os-unix-p) (:os-macosx . os-macosx-p) ; Beware,
unix must come first!
'''
Alexandru Popa
