Re: "error: unable to construct..."

From: David Abrahams (dave_at_[hidden])
Date: 2004-12-14 09:23:53

Vladimir Prus wrote:
> On Friday 10 December 2004 20:49, David Abrahams wrote:
>> Help! I'm getting some errors I don't know what to do with.
>>
>> cd /home/dave/src/osl/mtl4/libs/numeric/mtl/doc/
>> bjam -n -a
>>
>> /home/dave/boost/tools/build/v2/build/targets.jam:1237: in construct from
>> module object(typed-target)@1 error: unable to construct
>> ../../../../libs/numeric/mtl/doc/index
>> /home/dave/boost/tools/build/v2/build/targets.jam:1093: in
> 
> This message usually means that calling generators.construct returned nothing. 
> Whenever I see anything like that, I run bjam with the "--debug-generators" 
> option to see what's going on.

I'll try that.

>> Also, if I uncomment the commented line in the Jamfile, I get:
>>
>> /home/dave/boost/tools/build/v2/build/targets.jam:704: in generate-really
>> from module object(main-target)@1 error: failed to build
>> ../../../../libs/numeric/mtl/doc/index with properties because no
>> best-matching alternative could be found
> 
> Do you define two targets with the same name?

Possibly. Let me look again.

>> P.S. It's disconcerting to see ../../../../ junk in the BBv2 output; I
>> had hoped we'd squash that by now. It's embarrassing enough in BBv1.
> 
> It would be good to fix up, but is not possible in general. For 
> example ../../../../libs/numeric/mtl/doc/index might not be the same as ".".

Even when the current directory ends in libs/numeric/mtl/doc/index?
I thought I understood that and knew that it had something to do with
symlinks, but now I don't see it.

But there's no need to add the ../../../ string to a local path in the
first place. In fact, if what you just said is true, it proves my
point: adding that string may unintentionally cause us to point at a
different file.

-- 
Dave Abrahams
Boost Consulting
http://www.boost-consulting.com