[Boost-build] How do I get debug output for locale library testing?

Subject: [Boost-build] How do I get debug output for locale library testing?
From: Kuhl, Brian (brian.kuhl_at_[hidden])
Date: 2016-06-08 02:01:45

Hi,
I'm trying to add some logic to boost_1_59_0/libs/locale/Jamefile.v2 to look for the  ICU library in a different location.
But it's not working.
Is there a debug setting that lets me see these early configuration tests exact output, I can't find a log file?

Many thanks for help with this question and previous ones,

Brian Kuhl
Wind River

FYI
Here's what I have so far, additions in bold, starting around line 57:

ICU_PATH =  [ modules.peek : ICU_PATH ] ;
ICU_LINK =  [ modules.peek : ICU_LINK ] ;
local local_libdir = [ option.get libdir ] ;

if $(ICU_LINK)
{
    ICU_OPTS = <include>$(ICU_PATH)/include <linkflags>$(ICU_LINK) <dll-path>$(ICU_PATH)/bin <runtime-link>shared ;
    ICU64_OPTS = <include>$(ICU_PATH)/include <linkflags>$(ICU_LINK) <dll-path>$(ICU_PATH)/bin64 <runtime-link>shared ;
}
else
{
    searched-lib icuuc : :  <name>icuuc
                            <search>$(local_libdir)
                            <link>shared
                            <target-os>vxworks ;

    explicit icuuc ;

    ICU_OPTS =
      <library>icuuc/<link>shared
      <linkflags>-licuuc ;

    searched-lib icuuc : :  <name>icuuc
                            <search>$(ICU_PATH)/lib
                            <link>shared
                            <runtime-link>shared ;