Le 2017-10-08 22:03, john herrlin a écrit :
> Hey,
> 
> I am facing a problem with (openvpn-client-service) when trying to
> reconfigure the system.
> Its GuixSD on a x86-64, the system config is attached.
> 
> Backtrace:
> In srfi/srfi-1.scm:
>    592:29 19 (map1 (#<<service> type: #<service-type nscd 22f74b0…> …))
>    592:29 18 (map1 (#<<service> type: #<service-type guix 22f73c0…> …))
>    592:29 17 (map1 (#<<service> type: #<service-type urandom-seed…> …))
>    592:29 16 (map1 (#<<service> type: #<service-type syslog 22f74…> …))
>    592:29 15 (map1 (#<<service> type: #<service-type static-netwo…> …))
>    592:29 14 (map1 (#<<service> type: #<service-type mingetty 22f…> …))
>    592:29 13 (map1 (#<<service> type: #<service-type mingetty 22f…> …))
>    592:29 12 (map1 (#<<service> type: #<service-type mingetty 22f…> …))
>    592:29 11 (map1 (#<<service> type: #<service-type mingetty 22f…> …))
>    592:29 10 (map1 (#<<service> type: #<service-type mingetty 22f…> …))
>    592:29  9 (map1 (#<<service> type: #<service-type mingetty 22f…> …))
>    592:29  8 (map1 (#<<service> type: #<service-type console-font…> …))
>    592:17  7 (map1 (#<<service> type: #<service-type openvpn-clie…> …))
> In gnu/services/vpn.scm:
>    409:24  6 (_ #<<openvpn-client-configuration> openvpn: #<package …>)
>     379:9  5 (openvpn-config-file client #<<openvpn-client-configura…>)
> In ice-9/ports.scm:
>     549:4  4 (call-with-output-string _)
>     473:4  3 (with-output-to-port _ _)
> In ice-9/boot-9.scm:
>    268:13  2 (for-each #<procedure 2636d40 at gnu/services/configur…> 
> …)
> In gnu/services/vpn.scm:
>    112:19  1 (serialize-tls-auth client #f)
> In unknown file:
>            0 (string-append #f " " "1")
> 
> ERROR: In procedure string-append:
> ERROR: In procedure string-append: Wrong type (expecting string): #f

Although I won't be able to check it before tomorrow evening, here is a 
patch that should solve your issue. Are you able to test it and tell me 
whether it works?

Thank you for reporting this!