golang tool pprof not working properly - same broken output regardless of profiling target

I've previously used the pprof tool without issue and it worked great - now I see output like the following no matter what I profile:

the application being profiled in this example probably makes 40+ function calls and even more complex apps are producing similar callgraphs for both cpu and memprofiling.

The apps Im trying to profile are all web applications, I am profiling them for one minute at a time and using wrk to generate 200,000,000+ requests = all returning data and a 2xx response

pprof suddenly stopped working a few days ago running osx yosemite - in an attempt to resolve the issue I recently upgraded to el capitan but result is the same.

Note: this is not just call graphs - calling list or top command produce similarly barren results but the apps themselves work fine:

    (pprof) top
269.97kB of 269.97kB total (  100%)
      flat  flat%   sum%        cum   cum%
  269.97kB   100%   100%   269.97kB   100%  
(pprof) 

I am using the following package: "github.com/davecheney/profile" with go v1.5.1

For clarity, here's what I'm doing to generate the profiles::

I import the above package into main.go and place the following at the top of my main func:

defer profile.Start(profile.MemProfile).Stop()

I then build the binary and run it:

go build -o orig /Users/danielwall/www/netlistener/application/adrequest.go /Users/danielwall/www/netlistener/application/cookie.go /Users/danielwall/www/netlistener/application/header.go /Users/danielwall/www/netlistener/application/lex.go /Users/danielwall/www/netlistener/application/main.go /Users/danielwall/www/netlistener/application/publisher_ids.go /Users/danielwall/www/netlistener/application/request.go /Users/danielwall/www/netlistener/application/response.go /Users/danielwall/www/netlistener/application/server.go /Users/danielwall/www/netlistener/application/sniff.go /Users/danielwall/www/netlistener/application/status.go /Users/danielwall/www/netlistener/application/transfer.go

./orig

I then see output like this:

2015/11/16 11:39:49 profile: memory profiling enabled, /var/folders/26/2sj70_sn72l_93j7tf6r07gr0000gn/T/profile614358295/mem.pprof

Now I work the app from another terminal :

    wrk -d60 -c10 -H "X-Device: desktop" -H "X-Country-Code: GB" "http://localhost:8189/app?id=111&schema=xml2&ad_type=auto&url=http://test.com/&category=bob"
Running 1m test @ http://localhost:8189/app?id=111&schema=xml2&ad_type=auto&url=http://test.com/&category=bob
  2 threads and 10 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency   414.09us    0.92ms  55.36ms   95.66%
    Req/Sec    17.57k     3.19k   22.59k    76.00%
  2097764 requests in 1.00m, 684.20MB read
Requests/sec:  34958.03
Transfer/sec:     11.40MB

After 60 seconds, I go back to check my profile:

^C2015/11/16 12:05:20 profile: caught interrupt, stopping profiles

go tool pprof /var/folders/26/2sj70_sn72l_93j7tf6r07gr0000gn/T/profile614358295/mem.pprof

Any ideas what might be happening here or where I could start with trouble shooting/solving this?

Any help suggestions welcome.