running testsuite with PREFER_APPLETS=y and EXEC_PATH=

[Rich Felker]

On Sun, Nov 10, 2013 at 06:46:10PM +0400, Michael Tokarev wrote:
> Hello.
> 
> When running testsuite, we're trying to execute applets
> by their names, like "grep", "cp", "sh" and so on.
> 
> When CONFIG_BUSYBOX_PREFER_APPLETS set to "y", busybox
> tries to exec itself.  But this, in turn, depends on
> CONFIG_BUSYBOX_EXEC_PATH pointing to the right executable.
> On linux this is /proc/self/exe, but this obviously requires
> mounted /proc.  On other systems, this does not work.
> 
> On Debian we used "/bin/busybox" as BUSYBOX_EXEC_PATH,
> to work around not mounted /proc (since busybox is used
> as shell for initramfs), and for other systems without
> /proc/self support.
> 
> But this way, as long as our just-built busybox is not
> placed to /bin/busybox, we can't test it, we're testing
> system /bin/busybox (provided it actually exists),
> or system utilities (found in $PATH).
> 
> So now I'm basically lost.  I can re-set EXEC_PATH back to
> the default "/proc/self/exe", this will re-enable testsuite
> on linux correctly.  It will still fail on other systems
> (*bsd, solaris etc).
> 
> Any suggestion on this?

How about parsing the aux vector for AT_EXECFN and using that? It
could at least be an option. Or, busybox could just fallback to not
preferring applets when the exec of /proc/self/exe fails...

Rich