Flash Player for Icecat Gnash can not find boost header

[znavko]

Hello! I need to use Flash Player in IceCat on GNU GuixSD.
First I tried to download NPAPI from get.adobe.com and to place it into ~/.mozilla/plugins with `chmod +x libflashplayer.so`. But after  Icecat restart, flash player plugin does not appear.

Now I try to compile Gnash - GNU Flash alternative. I did not found it in repository:
$ guix package -s gnash
$ 

So I have downloaded and unzipped gnash-0.8.10. And try to compile as non-root user. I've installed boost for it , but gnash configure script does not find it:

$ guix package -i boost
The following package will be installed:
   boost    1.66.0    /gnu/store/l6hqfwr1hcbn9rg56bwn2d41g2ai36h2-boost-1.66.0

substitute: updating list of substitutes from 'https://mirror.hydra.gnu.org'... substitute: updating list of substitutes from 'https://mirror.hydra.gnu.org'... 100.0%
...
73 packages in profile

$ whereis boost
boost:

$ ls /gnu/store/l6hqfwr1hcbn9rg56bwn2d41g2ai36h2-boost-1.66.0
include/  lib/  share/

$ pwd
/home/bob/Downloads/gnash-0.8.10

$ ./configure
...
checking whether pthreads work with -pthread... yes
checking searching for pthread library... not found
checking for the Boost Version... 
checking for boost header... checking for Boost libraries... configure: WARNING: Libraries  thread program_options iostreams  serialization date_time aren't installed 

checking if -fvisibility-inlines-hidden is broken... no
checking whether g++ supports -fvisibility=hidden... yes
checking whether GConf support is requested... yes
checking for GCONF... configure: error: Package requirements (gconf-2.0) were not met.
Consider adjusting the PKG_CONFIG_PATH environment variable if you
installed software in a non-standard prefix.

Alternatively you may set the GCONF_CFLAGS and GCONF_LIBS environment variables
to avoid the need to call pkg-config.  See the pkg-config man page for
more details.


--
Please, what to do?