What does 'go version' print?
go version go1.4beta1 linux/amd64

What steps reproduce the problem?
go test database/sql -test.run=TestDrivers -test.cpu=4,4,4

What happened?
=== RUN TestDrivers-4
--- FAIL: TestDrivers-4 (0.00s)
panic: sql: Register called twice for driver invalid [recovered]
    panic: sql: Register called twice for driver invalid

goroutine 358 [running]:
testing.func·006()
    /home/gustav/go.tip/src/testing/testing.go:441 +0x181
database/sql.Register(0x5b9b10, 0x7, 0x7f008c2910d8, 0xc2081a7640)
    /home/gustav/go.tip/src/database/sql/sql.go:35 +0x135
database/sql.TestDrivers(0xc2081ca360)
    /home/gustav/go.tip/src/database/sql/fakedb_test.go:144 +0x96
testing.tRunner(0xc2081ca360, 0x695040)
    /home/gustav/go.tip/src/testing/testing.go:447 +0xbf
created by testing.RunTests
    /home/gustav/go.tip/src/testing/testing.go:555 +0xa8b

goroutine 1 [chan receive]:
testing.RunTests(0x609a88, 0x694fe0, 0x2c, 0x2c, 0x69a401)
    /home/gustav/go.tip/src/testing/testing.go:556 +0xad6
testing.(*M).Run(0xc2080560f0, 0x6a0e60)
    /home/gustav/go.tip/src/testing/testing.go:485 +0x6c
main.main()
    database/sql/_test/_testmain.go:156 +0x1d5
exit status 2
FAIL    database/sql    0.464s

What should have happened instead?
=== RUN TestDrivers-2
--- PASS: TestDrivers-2 (0.00s)