[Scons-users] Unexpected messge with configure

[Mats Wichmann]

On 09/07/2018 09:55 AM, Jason Kenny wrote:
> I was adding some configure logic to a build I am working on. When doing a dry run i now get this error:
> 
> scons: *** Cannot update configure test ".sconf_temp/conftest_0" within a dry-run.
> File "./../scons-3.0.1/SCons/Script/SConscript.py", line 614, in __call__
> 
> Is this a known issue with using configure in scons?

I've run into it (you'll find my name on such questions in the mailing
list archive, afair).

When you stop and think about it, running a configure test which means
compiling code sort of doesn't fit the definition of "dry run", though.

this is a gray area to my way of thinking.  steps like cleaning, getting
help, and doing a dry-run are places where you don't want external work
to happen, just have scons go through the rules.  but sometimes you
don't know what all the dependencies actually are before you've run some
of those steps.

we'll wait for the actual experts to pipe up :)

======
Aside:
on the project I'm trying to gradually bend into shape (it had lived for
a couple of years before I came around), which uses a variant directory
build, starting with the variant directory completely absent, "scons
--help" takes seven seconds, and leaves a variant directory with 12
object files and four libraries built. I *KNOW* that's wrong, but I
haven't yet figured out how to fix it without either breaking
everything, or special-casing stuff all over the place like

if not env.GetOption('help') and not env.GetOption('clean'):

guess we could put GetOption('dry-run') in that list too (would we have
to include all of the variants of that name? -n, --no-exec,
--just-print, --dry-run, --recon)

with 200+ sconscripts, adding those cases is not appealing.