sbcl-ningle: permission denied

[jgart]

Hi Guixers,

Just reporting this issue.

I had sbcl and sbcl-ningle in my profile.

When I try to build ningle I get the error below:

```
λ rlwrap sbcl
This is SBCL 2.1.9, an implementation of ANSI Common Lisp.
More information about SBCL is available at <http://www.sbcl.org/>.

SBCL is free software, provided as is, with absolutely no warranty.
It is mostly in the public domain; some portions are provided under
BSD-style licenses.  See the CREDITS and COPYING files in the
distribution for more information.
CL-USER(1): (asdf:make :ningle)
WARNING: System definition file 
#P"/gnu/store/zwkhqlyijf8bwpm3a70f7ly978w2knqw-sbcl-flexi-streams-1.0.19/share/common-lisp/sbcl/flexi-streams/flexi-streams.asd"
 contains definition for system "flexi-streams-test". Please only define 
"flexi-streams" and secondary systems with a name starting with 
"flexi-streams/" (e.g. "flexi-streams/test") in that file.

debugger invoked on a SB-INT:SIMPLE-FILE-ERROR in thread
#<THREAD "main thread" RUNNING {100B790173}>:
  Error opening 
#P"/gnu/store/8jn98z4pr2r9dglsw37a70y8nl6ksb9i-sbcl-ningle-0.3.0-1.50bd4f0/lib/common-lisp/sbcl/ningle/context-tmpGHU3ALSV.fasl":

    Permission denied

Type HELP for debugger help, or (SB-EXT:EXIT) to exit from SBCL.

restarts (invokable by number or by possibly-abbreviated name):
  0: [CONTINUE                     ] Retry opening.
  1: [USE-VALUE                    ] Try opening a different file.
  2: [RETRY                        ] Retry
                                     compiling #<CL-SOURCE-FILE 
"ningle/context" "file-type">.
  3: [ACCEPT                       ] Continue, treating
                                     compiling #<CL-SOURCE-FILE 
"ningle/context" "file-type">
                                     as having been successful.
  4:                                 Retry ASDF operation.
  5: [CLEAR-CONFIGURATION-AND-RETRY] Retry ASDF operation after resetting the
                                     configuration.
  6:                                 Retry ASDF operation.
  7:                                 Retry ASDF operation after resetting the
                                     configuration.
  8: [ABORT                        ] Exit debugger, returning to top level.

(SB-IMPL::FILE-PERROR 
#P"/gnu/store/8jn98z4pr2r9dglsw37a70y8nl6ksb9i-sbcl-ningle-0.3.0-1.50bd4f0/lib/common-lisp/sbcl/ningle/context-tmpGHU3ALSV.fasl"
 13 "Error opening ~S" 
#P"/gnu/store/8jn98z4pr2r9dglsw37a70y8nl6ksb9i-sbcl-ningle-0.3.0-1.50bd4f0/lib/common-lisp/sbcl/ningle/context-tmpGHU3ALSV.fasl")
```

WDYT?