I just got this from `guix pull`:

guix pull --url=file:///gnu/store/l552m9iavw3amq5c8vaifqlxvw09r2nz-guix-latest.tar.gz
unpacking '/gnu/store/l552m9iavw3amq5c8vaifqlxvw09r2nz-guix-latest.tar.gz'...
updating list of substitutes from 'https://4606.nsupdate.info'... 100.0%o'...   0.0%
The following derivation will be built:
   /gnu/store/xxy7l4jfjx6n62anfqlw4gbmafypqgrs-guix-latest.drv
updating list of substitutes from 'https://4606.nsupdate.info'... 100.0%o'...   0.0%
substitute: updating list of substitutes from 'https://mirror.hydra.gnu.org'... 100.0%
copying and compiling to '/gnu/store/r1z6nbkrl99hxppcvcprc8vgbzakv632-guix-latest' with Guile 2.2.2...
loading...	 25.4% of 606 filesrandom seed for tests: 1498319917
loading...	 99.8% of 606 files
compiling...	 99.2% of 606 filesBacktrace:
           2 (primitive-load "/gnu/store/v9a9cqzh41qg4sixl2mk5kndglp?")
In ./guix/build/pull.scm:
    181:8  1 (build-guix _ _ #:system _ #:storedir _ #:localstatedir ?)
In ice-9/threads.scm:
   289:22  0 (loop _)

ice-9/threads.scm:289:22: In procedure loop:
ice-9/threads.scm:289:22: Wrong type (expecting mutex): (3556 . #<procedure intset-add (bs i)>)

Some deprecated features have been used.  Set the environment
variable GUILE_WARN_DEPRECATED to "detailed" and rerun the
program to get more information.  Set it to "no" to suppress
this message.
builder for `/gnu/store/xxy7l4jfjx6n62anfqlw4gbmafypqgrs-guix-latest.drv' failed with exit code 1
guix pull: error: build failed: build of `/gnu/store/xxy7l4jfjx6n62anfqlw4gbmafypqgrs-guix-latest.drv' failed