Re: [boost] [EXTERNAL] [testing] mpl/core tests not visible

Subject: Re: [boost] [EXTERNAL] [testing] mpl/core tests not visible
From: Belcourt, Kenneth (kbelco_at_[hidden])
Date: 2014-09-13 17:25:58

On Sep 13, 2014, at 3:11 PM, Andrey Semashev <andrey.semashev_at_[hidden]> wrote:

> On Saturday 13 September 2014 20:46:40 Belcourt, Kenneth wrote:
>> 
>> Looks like a change in how b2 runs.  IIRC, running b2, without specifying
>> the headers target, would look for the boost directory and, if not found,
>> would run the headers target, and then proceed with the build.  It now
>> seems that if b2 is run (no boost directory and no header target specified
>> on the command line), only about 250 files are installed into the boost
>> directory, and then b2 starts compiling code.  An explicit 'b2 headers'
>> installs over 1300 headers.
> 
> So, to be clear, with explicit 'b2 headers' it compiles as expected?

Yes.

> This is the source of the nightly testing problem, the run script doesn’t
>> explicitly invoke ‘b2 headers’, it first builds b2 then proceeds to build
>> process_jam_log resulting in a subset of headers being installed and
>> process_jam_log.cpp failing to compile due to missing headers.
>> 
>> Most / all non-Linux develop testers have stopped cycling so it seems we
>> need to get this fixed ASAP.  One possible resolution is to not try to
>> figure out the change in b2 behavior and fix the nightly testing to
>> explicitly invoke ‘b2 headers’.  I suspect that would get the testers
>> cycling again.  Not sure how users might feel about the change in b2
>> behavior though.
> 
> I suppose, the expectation is that b2 will infer the dependent headers from 
> the compiled sources somehow and installs them. It's possible that it is not 
> able to pass through the preprocessor magic used in MPL. I think there was a 
> discussion some time ago about some headers not being automatically installed 
> this way. Although that doesn't explain why only some testers were broken.

It’s because I don’t remove the existing boost directory so it’s already fully (correctly) populated.  These testers will also fail if I remove their boost directories.

> Anyway, IMHO, 'b2 headers' should be explicitly invoked by the testing 
> scripts.

Right, testers would be okay with that though I think a breaking change like this needs a bit more visibility so that testers, developers, and others, understand this change.

— Noel