I've stress tested net/http with -cpu=1,2,4,8,16,32,64,128 and some tests episodically
crash with the following reports. The reason seems to be simply that the tests do not
check errors. Here are the crashes:


--- FAIL: TestStressSurpriseServerCloses (62.49s)
    transport_test.go:513: presumed deadlock; no HTTP client activity seen in awhile
--- FAIL: TestRoundTripGzip (30.01s)
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
    panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x0 pc=0x517173]
goroutine 27995 [running]:
runtime.gopanic(0x7ca9a0, 0xc20802c050)
    /ssd/src/go1/src/runtime/panic.go:429 +0x2ef fp=0xc208a47b78 sp=0xc208a47b10
testing.func·006()
    /ssd/src/go1/src/testing/testing.go:442 +0x181 fp=0xc208a47c08 sp=0xc208a47b78
runtime.call16(0xc208a47fa0, 0xc2081ce360, 0x0)
    /ssd/src/go1/src/runtime/asm_amd64.s:388 +0x45 fp=0xc208a47c20 sp=0xc208a47c08
runtime.gopanic(0x7ca9a0, 0xc20802c050)
    /ssd/src/go1/src/runtime/panic.go:391 +0x3f4 fp=0xc208a47c88 sp=0xc208a47c20
runtime.panicmem()
    /ssd/src/go1/src/runtime/panic.go:42 +0x4e fp=0xc208a47cb0 sp=0xc208a47c88
runtime.sigpanic()
    /ssd/src/go1/src/runtime/sigpanic_unix.go:24 +0x297 fp=0xc208a47cf0 sp=0xc208a47cb0
net/http_test.TestRoundTripGzip(0xc2084f6630)
    /ssd/src/go1/src/net/http/transport_test.go:636 +0x1173 fp=0xc208a47f78 sp=0xc208a47cf0
testing.tRunner(0xc2084f6630, 0xa59878)
    /ssd/src/go1/src/testing/testing.go:448 +0xbf fp=0xc208a47fd0 sp=0xc208a47f78
runtime.goexit()
    /ssd/src/go1/src/runtime/asm_amd64.s:2219 +0x1 fp=0xc208a47fd8 sp=0xc208a47fd0
created by testing.RunTests
    /ssd/src/go1/src/testing/testing.go:559 +0xa8b



--- FAIL: TestTimeoutHandler-16 (30.00s)
    serve_test.go:1186: Get http://127.0.0.1:56230: dial tcp 127.0.0.1:56230: i/o timeout
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
    panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x10 pc=0x4f6811]
goroutine 89024 [running]:
runtime.gopanic(0x7ca9a0, 0xc20802c050)
    /ssd/src/go1/src/runtime/panic.go:429 +0x2ef fp=0xc208857c20 sp=0xc208857bb8
testing.func·006()
    /ssd/src/go1/src/testing/testing.go:442 +0x181 fp=0xc208857cb0 sp=0xc208857c20
runtime.call16(0xc208857fa0, 0xc20897e150, 0x0)
    /ssd/src/go1/src/runtime/asm_amd64.s:388 +0x45 fp=0xc208857cc8 sp=0xc208857cb0
runtime.gopanic(0x7ca9a0, 0xc20802c050)
    /ssd/src/go1/src/runtime/panic.go:391 +0x3f4 fp=0xc208857d30 sp=0xc208857cc8
runtime.panicmem()
    /ssd/src/go1/src/runtime/panic.go:42 +0x4e fp=0xc208857d58 sp=0xc208857d30
runtime.sigpanic()
    /ssd/src/go1/src/runtime/sigpanic_unix.go:24 +0x297 fp=0xc208857d98 sp=0xc208857d58
net/http_test.TestTimeoutHandler(0xc208079d40)
    /ssd/src/go1/src/net/http/serve_test.go:1188 +0x381 fp=0xc208857f78 sp=0xc208857d98
testing.tRunner(0xc208079d40, 0xa59350)
    /ssd/src/go1/src/testing/testing.go:448 +0xbf fp=0xc208857fd0 sp=0xc208857f78
runtime.goexit()
    /ssd/src/go1/src/runtime/asm_amd64.s:2219 +0x1 fp=0xc208857fd8 sp=0xc208857fd0
created by testing.RunTests
    /ssd/src/go1/src/testing/testing.go:559 +0xa8b



--- FAIL: TestStressSurpriseServerCloses (66.64s)
    transport_test.go:513: presumed deadlock; no HTTP client activity seen in awhile
--- FAIL: TestRoundTripGzip (30.01s)
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
    panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x0 pc=0x517173]
goroutine 28912 [running]:
runtime.gopanic(0x7ca9a0, 0xc20802c050)
    /ssd/src/go1/src/runtime/panic.go:429 +0x2ef fp=0xc2088f1b78 sp=0xc2088f1b10
testing.func·006()
    /ssd/src/go1/src/testing/testing.go:442 +0x181 fp=0xc2088f1c08 sp=0xc2088f1b78
runtime.call16(0xc2088f1fa0, 0xc2084f0390, 0x0)
    /ssd/src/go1/src/runtime/asm_amd64.s:388 +0x45 fp=0xc2088f1c20 sp=0xc2088f1c08
runtime.gopanic(0x7ca9a0, 0xc20802c050)
    /ssd/src/go1/src/runtime/panic.go:391 +0x3f4 fp=0xc2088f1c88 sp=0xc2088f1c20
runtime.panicmem()
    /ssd/src/go1/src/runtime/panic.go:42 +0x4e fp=0xc2088f1cb0 sp=0xc2088f1c88
runtime.sigpanic()
    /ssd/src/go1/src/runtime/sigpanic_unix.go:24 +0x297 fp=0xc2088f1cf0 sp=0xc2088f1cb0
net/http_test.TestRoundTripGzip(0xc20893a630)
    /ssd/src/go1/src/net/http/transport_test.go:636 +0x1173 fp=0xc2088f1f78 sp=0xc2088f1cf0
testing.tRunner(0xc20893a630, 0xa59878)
    /ssd/src/go1/src/testing/testing.go:448 +0xbf fp=0xc2088f1fd0 sp=0xc2088f1f78
runtime.goexit()
    /ssd/src/go1/src/runtime/asm_amd64.s:2219 +0x1 fp=0xc2088f1fd8 sp=0xc2088f1fd0
created by testing.RunTests
    /ssd/src/go1/src/testing/testing.go:559 +0xa8b