I did a bit more digging and found some interesting behavior on sbcl.
Whether or not the output is propagated to a stream in the event of an
error is dependant on shell vs. exec:
(uiop:run-program "echo hi >&2; false" :error-output t) ; No output
(uiop:run-program '("/bin/sh" "-c" "echo hi >&2; false" ) :error-output t) ;
"hi\n" on *error-output*
-Jason
On 10:44 Fri 09 Sep , Jason Miller wrote:
> Hi,
>
> A lot of times the most useful information when an external program
> returns an error is the stderr output. However, I can't figure out any
> way to get this without setting :ignore-error-status to T.
>
> In particular I feel things would be strictly better if every invocation
> of the form:
>
> (run-program ... :error-output t)
>
> Acted more like:
>
> (let ((result (multiple-value-list (run-program
> :error-output t
> :ignore-error-status t))))
> (when (not (zerop (caddr result))) (cerror ...))
> (values-list result))
>
> The former prints no output to *error-output* in the event of non-zero
> return, but the latter prints all the output.
>
> There may be a better way of doing this (including the error file or
> output in the condition object perhaps?), so I'm open to alternatives.
> Any thoughts?
>
> -Jason
>
