[boost] [build] File / path lengths difficult to manage on Windows

Subject: [boost] [build] File / path lengths difficult to manage on Windows
From: Ben Craig (ben.craig_at_[hidden])
Date: 2013-11-13 09:16:38

I was unzipping boost 1.55 on my Windows machine, into what I thought was 
a reasonable location.  7-zip eventually complained about a file that it 
could not write because the path was too long.  Most APIs on Windows 
restrict paths to ~260 characters.  The longest file in the boost 1.55 
release is the following:

boost_1_55_0\libs\geometry\doc\html\geometry\reference\spatial_indexes\boost__geometry__index__rtree\rtree_parameters_type_const____indexable_getter_const____value_equal_const____allocator_type_const___.html

This is 207 characters long.  Next on the list are a whole bunch of html 
and png documentation files, all with length 174.  Here is one example:

boost_1_55_0\doc\html\images\accumulators\structboost_1_1accumulators_1_1detail_1_1is__tail__variate__feature_3_01tag_1_1tail__variate_3_01bd5040caa5e48b0af425af2314206bf.png

As you may notice, the end of that particular file ends in a uuid / guid. 
It may be as easy as making that uuid appear 30 or 40 characters sooner in 
the path.

**************************************************************************************************************
Is it unreasonable to ask that the boost zip only use half (130 
characters) of the available Windows path size for itself?
**************************************************************************************************************

On a related note, is it unreasonable to ask that an --abbreviate-paths 
build of boost limit itself to 130 characters?  I acknowledge that this 
one is a bit harder to solve as there can be a large number of build 
"pivots" that all add to the path, but some clients (like me) need to 
layer other build pivot and version information on top of what boost 
already provides, and I need some amount of character wiggle room to make 
that happen.

This isn't currently in as bad of a shape as the zip file.  For an 
outdated piece of information, my win64 builds of boost 1.50 have a path 
part of 151 characters.

boost\bin.v2\libs\test\build\msvc-11.0\rls\adrs-mdl-64\async-excpt-on\dbg-symbl-on\lnk-sttc\thrd-mlt\libboost_unit_test_framework-vc110-mt-1_50.lib.rsp

Is there significant value in putting "bin.v2\libs" in the path?