runtime: TestGdbBacktrace failures

[gopherbot]

#!watchflakes
post <- pkg == "runtime" && test == "TestGdbBacktrace" && (`No child processes` || `No such process`)

Issue created automatically to collect these failures.

Example (log):

--- FAIL: TestGdbBacktrace (2323.65s)
    runtime-gdb_test.go:83: gdb version 10.1
    runtime-gdb_test.go:468: GDB command timed out after 38m43.017693938s: /usr/bin/gdb -nx -batch -iex add-auto-load-safe-path /workdir/go/src/runtime -ex set startup-with-shell off -ex break main.eee -ex run -ex backtrace -ex continue /workdir/tmp/TestGdbBacktrace2238907183/001/a.exe
    runtime-gdb_test.go:473: gdb output:
        Loading Go Runtime support.
        Breakpoint 1 at 0x80a2830: file /workdir/tmp/TestGdbBacktrace2238907183/001/main.go, line 17.
        [New LWP 532860]
        [New LWP 532862]
        [New LWP 532864]
        [New LWP 532865]

        Thread 1 "a.exe" hit Breakpoint 1, main.eee (~r0=<optimized out>) at /workdir/tmp/TestGdbBacktrace2238907183/001/main.go:17
        17	func eee() bool { return true }
        #0  main.eee (~r0=<optimized out>) at /workdir/tmp/TestGdbBacktrace2238907183/001/main.go:17
        #1  0x080a280f in main.ddd (~r0=<optimized out>) at /workdir/tmp/TestGdbBacktrace2238907183/001/main.go:14
        #2  0x080a27da in main.ccc (~r0=<optimized out>) at /workdir/tmp/TestGdbBacktrace2238907183/001/main.go:11
        #3  0x080a27aa in main.bbb (~r0=<optimized out>) at /workdir/tmp/TestGdbBacktrace2238907183/001/main.go:8
        #4  0x080a277a in main.aaa (~r0=<optimized out>) at /workdir/tmp/TestGdbBacktrace2238907183/001/main.go:5
        #5  0x080a286a in main.main () at /workdir/tmp/TestGdbBacktrace2238907183/001/main.go:22
        waiting for new child: No child processes.
    runtime-gdb_test.go:488: gdb exited with error: signal: killed

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- pkg == "runtime" && test == "TestGdbBacktrace"

2023-02-13 19:42 linux-386-longtest go@0b922bfa runtime.TestGdbBacktrace (log)

--- FAIL: TestGdbBacktrace (2323.65s)
    runtime-gdb_test.go:83: gdb version 10.1
    runtime-gdb_test.go:468: GDB command timed out after 38m43.017693938s: /usr/bin/gdb -nx -batch -iex add-auto-load-safe-path /workdir/go/src/runtime -ex set startup-with-shell off -ex break main.eee -ex run -ex backtrace -ex continue /workdir/tmp/TestGdbBacktrace2238907183/001/a.exe
    runtime-gdb_test.go:473: gdb output:
        Loading Go Runtime support.
        Breakpoint 1 at 0x80a2830: file /workdir/tmp/TestGdbBacktrace2238907183/001/main.go, line 17.
        [New LWP 532860]
        [New LWP 532862]
        [New LWP 532864]
        [New LWP 532865]

        Thread 1 "a.exe" hit Breakpoint 1, main.eee (~r0=<optimized out>) at /workdir/tmp/TestGdbBacktrace2238907183/001/main.go:17
        17	func eee() bool { return true }
        #0  main.eee (~r0=<optimized out>) at /workdir/tmp/TestGdbBacktrace2238907183/001/main.go:17
        #1  0x080a280f in main.ddd (~r0=<optimized out>) at /workdir/tmp/TestGdbBacktrace2238907183/001/main.go:14
        #2  0x080a27da in main.ccc (~r0=<optimized out>) at /workdir/tmp/TestGdbBacktrace2238907183/001/main.go:11
        #3  0x080a27aa in main.bbb (~r0=<optimized out>) at /workdir/tmp/TestGdbBacktrace2238907183/001/main.go:8
        #4  0x080a277a in main.aaa (~r0=<optimized out>) at /workdir/tmp/TestGdbBacktrace2238907183/001/main.go:5
        #5  0x080a286a in main.main () at /workdir/tmp/TestGdbBacktrace2238907183/001/main.go:22
        waiting for new child: No child processes.
    runtime-gdb_test.go:488: gdb exited with error: signal: killed

— watchflakes

[mknyszek]

In triage, best guess is that this is just a "GDB tests are sometimes flaky" but we'll wait on more failures.

Than and Cherry note that the GDB version isn't very old.

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- pkg == "runtime" && test == "TestGdbBacktrace"

2023-03-16 19:44 linux-arm64 go@19281498 runtime.TestGdbBacktrace (log)

--- FAIL: TestGdbBacktrace (0.33s)
    runtime-gdb_test.go:81: gdb version 10.1
    runtime-gdb_test.go:471: gdb output:
        Loading Go Runtime support.
        Breakpoint 1 at 0x64e84: file /tmp/workdir/tmp/TestGdbBacktrace2506571992/001/main.go, line 17.
        [New LWP 180945]
        [New LWP 180946]
        [New LWP 180947]

        Thread 1 "a.exe" hit Breakpoint 1, 0x0000000000064e84 in main.eee (~r0=<optimized out>) at /tmp/workdir/tmp/TestGdbBacktrace2506571992/001/main.go:17
        17	func eee() bool { return true }
        #0  0x0000000000064e84 in main.eee (~r0=<optimized out>) at /tmp/workdir/tmp/TestGdbBacktrace2506571992/001/main.go:17
        #1  0x0000000000064e68 in main.ddd (~r0=<optimized out>) at /tmp/workdir/tmp/TestGdbBacktrace2506571992/001/main.go:14
        #2  0x0000000000064e1c in main.ccc (~r0=<optimized out>) at /tmp/workdir/tmp/TestGdbBacktrace2506571992/001/main.go:11
        #3  0x0000000000064ddc in main.bbb (~r0=<optimized out>) at /tmp/workdir/tmp/TestGdbBacktrace2506571992/001/main.go:8
        #4  0x0000000000064d9c in main.aaa (~r0=<optimized out>) at /tmp/workdir/tmp/TestGdbBacktrace2506571992/001/main.go:5
        #5  0x0000000000064eac in main.main () at /tmp/workdir/tmp/TestGdbBacktrace2506571992/001/main.go:22
        Unable to fetch general registers.: No such process.
        [LWP 180947 exited]
        [LWP 180945 exited]
        [LWP 180940 exited]
    runtime-gdb_test.go:486: gdb exited with error: exit status 1

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- pkg == "runtime" && test == "TestGdbBacktrace"

2023-03-16 19:51 linux-arm64-boringcrypto go@e91876f4 runtime.TestGdbBacktrace (log)

--- FAIL: TestGdbBacktrace (0.28s)
    runtime-gdb_test.go:81: gdb version 10.1
    runtime-gdb_test.go:471: gdb output:
        Loading Go Runtime support.
        Breakpoint 1 at 0x64e84: file /tmp/workdir/tmp/TestGdbBacktrace4270477819/001/main.go, line 17.
        [New LWP 188825]
        [New LWP 188826]
        [New LWP 188827]

        Thread 1 "a.exe" hit Breakpoint 1, 0x0000000000064e84 in main.eee (~r0=<optimized out>) at /tmp/workdir/tmp/TestGdbBacktrace4270477819/001/main.go:17
        17	func eee() bool { return true }
        #0  0x0000000000064e84 in main.eee (~r0=<optimized out>) at /tmp/workdir/tmp/TestGdbBacktrace4270477819/001/main.go:17
        #1  0x0000000000064e68 in main.ddd (~r0=<optimized out>) at /tmp/workdir/tmp/TestGdbBacktrace4270477819/001/main.go:14
        #2  0x0000000000064e1c in main.ccc (~r0=<optimized out>) at /tmp/workdir/tmp/TestGdbBacktrace4270477819/001/main.go:11
        #3  0x0000000000064ddc in main.bbb (~r0=<optimized out>) at /tmp/workdir/tmp/TestGdbBacktrace4270477819/001/main.go:8
        #4  0x0000000000064d9c in main.aaa (~r0=<optimized out>) at /tmp/workdir/tmp/TestGdbBacktrace4270477819/001/main.go:5
        #5  0x0000000000064eac in main.main () at /tmp/workdir/tmp/TestGdbBacktrace4270477819/001/main.go:22
        Unable to fetch general registers.: No such process.
        [LWP 188827 exited]
        [LWP 188825 exited]
        [LWP 188822 exited]
    runtime-gdb_test.go:486: gdb exited with error: exit status 1

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- pkg == "runtime" && test == "TestGdbBacktrace"

2023-03-30 18:50 linux-amd64 go@8890c3a0 runtime.TestGdbBacktrace (log)

--- FAIL: TestGdbBacktrace (148.14s)
    runtime-gdb_test.go:81: gdb version 10.1
    runtime-gdb_test.go:466: GDB command timed out after 2m27.709563668s: /usr/bin/gdb -nx -batch -iex add-auto-load-safe-path /workdir/go/src/runtime -ex set startup-with-shell off -ex break main.eee -ex run -ex backtrace -ex continue /workdir/tmp/TestGdbBacktrace732529650/001/a.exe
    runtime-gdb_test.go:471: gdb output:
        Loading Go Runtime support.
        Breakpoint 1 at 0x455180: file /workdir/tmp/TestGdbBacktrace732529650/001/main.go, line 17.
        [New LWP 69987]
        [New LWP 69988]
        [New LWP 69989]

        Thread 1 "a.exe" hit Breakpoint 1, main.eee (~r0=<optimized out>) at /workdir/tmp/TestGdbBacktrace732529650/001/main.go:17
        17	func eee() bool { return true }
        #0  main.eee (~r0=<optimized out>) at /workdir/tmp/TestGdbBacktrace732529650/001/main.go:17
        #1  0x0000000000455176 in main.ddd (~r0=<optimized out>) at /workdir/tmp/TestGdbBacktrace732529650/001/main.go:14
        #2  0x000000000045514f in main.ccc (~r0=<optimized out>) at /workdir/tmp/TestGdbBacktrace732529650/001/main.go:11
        #3  0x000000000045512f in main.bbb (~r0=<optimized out>) at /workdir/tmp/TestGdbBacktrace732529650/001/main.go:8
        #4  0x000000000045510f in main.aaa (~r0=<optimized out>) at /workdir/tmp/TestGdbBacktrace732529650/001/main.go:5
        #5  0x00000000004551af in main.main () at /workdir/tmp/TestGdbBacktrace732529650/001/main.go:22
        waiting for new child: No child processes.
    runtime-gdb_test.go:486: gdb exited with error: signal: killed

— watchflakes

[bcmills]

https://storage.googleapis.com/go-build-log/c6e62ba1/linux-arm64_2690be7d.log (a TryBot)

[bcmills]

In triage, best guess is that this is just a "GDB tests are sometimes flaky" but we'll wait on more failures.

Even if the problem is “GDB tests are sometimes flaky”, arguably they ought to skip in case of known failure modes.

(At the very least, there ought to be specific upstream issues we can refer to for the failures — if the problem is upstream and we don't report it, then it presumably won't ever get fixed.)