This is currently happens on race builders:
http://build.golang.org/log/85d4aef0d640cb600ec7e67be890b71db3114663

--- FAIL: TestRace (3.00 seconds)
    race_test.go:45: Failed to run tests: exit status 1
        runtime: invalid pc-encoded table f=runtime.gosched0 pc=0x419483 targetpc=0x41948f tab=0x8b1548
        fatal error: invalid runtime symbol table
        
        goroutine 3 [running]:
        runtime.throw(0xb6920d)
            /usr/local/go/src/pkg/runtime/panic.c:484 +0x69 fp=0x7fa43879fc68
        pcvalue(0x8b1500, 0x44, 0x41948f)
            /usr/local/go/src/pkg/runtime/symtab.c:142 +0x130 fp=0x7fa43879fcd8
        runtime.funcline(0x8b1500, 0x41948f, 0x7fa43879fd30)
            /usr/local/go/src/pkg/runtime/symtab.c:155 +0x53 fp=0x7fa43879fd00
        runtime.funcline_go(0x8b1500, 0x41948f, 0xb6922a, 0x1, 0x41948f)
            /usr/local/go/src/pkg/runtime/symtab.c:193 +0x3b fp=0x7fa43879fd20
        runtime.(*Func).FileLine(0x8b1500, 0x41948f, 0x0, 0x0, 0x0)
            /usr/local/go/src/pkg/runtime/extern.go:104 +0x43 fp=0x7fa43879fd50
        runtime/race.__tsan_symbolize(0x41948f, 0x7fa436ee9b70, 0x7fa436ee9b78, 0x7fa436ee9b8c, 0x7fa436ee9b80, ...)
            /tmp/gobuilder/linux-amd64-race-dc24634de6c5/go/src/pkg/runtime/race/race.go:115 +0xbf fp=0x7fa43879fda0
        ----- stack segment boundary -----
        runtime.cgocallbackg(0x7fa436ee9aa0, 0x7fa436ee9b20, 0x30)
            /usr/local/go/src/pkg/runtime/cgocall.c:237 +0x51 fp=0x7fa43879fe80
        runtime.cgocallback_gofunc(0x4049b5, 0x66fe80, 0x7fa43879ff18)
            /usr/local/go/src/pkg/runtime/asm_amd64.s:625 +0x74 fp=0x7fa43879feb0
        runtime.asmcgocall(0x66fe80, 0x7fa43879ff18)
            /usr/local/go/src/pkg/runtime/asm_amd64.s:520 +0x2d fp=0x7fa43879feb8
        runtime.cgocall(0x66fe80, 0x7fa43879ff18)
            /usr/local/go/src/pkg/runtime/cgocall.c:116 +0x45 fp=0x7fa43879ff00
        runtime/race._Cfunc___tsan_read_range(0x7fa4376ec018, 0xc210000228, 0x8, 0x0, 0x4707d9)
            runtime/race/_obj/_cgo_defun.c:151 +0x31 fp=0x7fa43879ff18
        runtime/race.ReadRange(0x7fa4376ec018, 0xc210000228, 0x8, 0x4707d9)
            /tmp/gobuilder/linux-amd64-race-dc24634de6c5/go/src/pkg/runtime/race/race.go:59 +0x4e fp=0x7fa43879ff48
        runtime.racereadrange(0xc210000228, 0x8)
            /usr/local/go/src/pkg/runtime/race.c:110 +0x71 fp=0x7fa43879ff78
        command-line-arguments_test.func·283()
            /usr/local/go/src/pkg/runtime/race/testdata/regression_test.go:20 +0x49 fp=0x7fa43879ffa0
        runtime.goexit()
            /usr/local/go/src/pkg/runtime/proc.c:1289 fp=0x7fa43879ffa8
        created by command-line-arguments_test.NewLog
            /usr/local/go/src/pkg/runtime/race/testdata/regression_test.go:22 +0x113

Race detector makes cgo callback and tries to symbolize pc from the callback.
I suspect this is broken w/o race detector as well (GC from cgo callback should have the
same effect), we just don't have such tests.