Developing Guile with Guix

[Andy Wingo]

Hi again :)  Still trying to figure out this Guix thing.

So for Guile I've gotten used to building and installing in /opt, when
working on Guile for development purposes.  Works pretty OK.  I know
there are many ways of doing this but it doesn't seem a priori a bad
thing to continue working this way.

In this regard "guix environment" is great as a first step.  "guix
environment guile" and configure and make and all is grand.  I will
still probably switch to a more profile-based strategy though because
"guix environment guile" will pull in whatever the latest deps are of
Guile, whereas usually when I work I want Guile to be the only thing I
am changing, and the system stays the same underneath.  Profiles give me
this, and give me the ability to control when I change the underlying
system.

Anyway so far so good.  However I can't install to /opt/guile:

    make[4]: Nothing to be done for 'install-exec-am'.
     /gnu/store/c158g4fki606z1g0l240kknprfwdls0a-coreutils-8.24/bin/mkdir -p 
'/opt/guile/lib/guile/2.2/extensions'
     /bin/sh ../libtool   --mode=install 
/gnu/store/c158g4fki606z1g0l240kknprfwdls0a-coreutils-8.24/bin/install -c   
guile-readline.la '/opt/guile/lib/guile/2.2/extensions'
    libtool: warning: relinking 'guile-readline.la'
    libtool: install: (cd /home/wingo/src/guile/guile-readline; /bin/sh 
"/home/wingo/src/guile/libtool"  --silent --tag CC --mode=relink ccache gcc 
-Wall -Wmissing-prototypes -Wdeclaration-after-statement -Wpointer-arith 
-Wswitch-enum -fno-strict-aliasing -fwrapv 
-I/gnu/store/ja9r9j3hn40gdn8wrj7vac3k28gdzail-libgc-7.4.2/include -g -O2 
-export-dynamic -no-undefined -module -o guile-readline.la -rpath 
/opt/guile/lib/guile/2.2/extensions readline.lo -lreadline -lncurses 
../libguile/libguile-2.2.la ../lib/libgnu.la -lcrypt -lm )
    ld-wrapper: error: attempt to use impure library 
"/opt/guile/lib/libguile-2.2.so"
    collect2: error: ld returned 1 exit status
    libtool:   error: error: relink 'guile-readline.la' with the above command 
before installing it

the salient line being:

    ld-wrapper: error: attempt to use impure library 
"/opt/guile/lib/libguile-2.2.so"

What do I do here?  Linking against /opt/guile/lib/libguile-2.2.so is
*exactly* what I want to do, so not quite sure how to proceed.  I *also*
want the resulting binary fixed up to link via -rpath into the store, so
I do need the ld-wrapper AFAIU, but I guess I need for it to allow
linking into /opt.

Any ideas?

Andy