cmd/compile: TestGdbPythonCgo fails with clang15 due to missing DWARF type information #72152

linsite · 2025-03-07T05:02:33Z

Go version

go version go1.24.1 linux/arm64

Output of `go env` in your module/workspace:

AR='ar'
CC='gcc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='g++'
GCCGO='gccgo'
GO111MODULE='on'
GOARCH='arm64'
GOARM64='v8.0'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/home/ulin/.cache/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/home/ulin/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build1130356347=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='arm64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/dev/null'
GOMODCACHE='/home/ulin/gosrc/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/home/ulin/gosrc'
GOPRIVATE=''
GOPROXY='https://goproxy.cn'
GOROOT='/usr/local/go'
GOSUMDB='off'
GOTELEMETRY='on'
GOTELEMETRYDIR='/home/ulin/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_arm64'
GOVCS=''
GOVERSION='go1.24.1'
GOWORK=''
PKG_CONFIG='pkg-config'

GDB

$ gdb --version
GNU gdb (Ubuntu 9.2-0ubuntu1~20.04.2) 9.2
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later http://gnu.org/licenses/gpl.html
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

What did you do?

CC=/usr/bin/clang-15 go test runtime -run TestGdbPythonCgo

What did you see happen?

Failed


--- FAIL: TestGdbPythonCgo (7.19s)                                                                                                                                                              runtime-gdb_test.go:79: gdb version 9.2                                                                                                                                                     runtime-gdb_test.go:339: gdb output:                                                                                                                                                            Dwarf Error: DW_FORM_strx1 found in non-DWO CU [in module /tmp/TestGdbPythonCgo1034027560/001/a.exe]
        Loading Go Runtime support.                                                                                                                                                                 Loading Go Runtime support.
        No symbol table is loaded.  Use the "file" command.
        Make breakpoint pending on future shared library load? (y or [n]) [answered N; input not from terminal]
        [Thread debugging using libthread_db enabled]                                                                                                                                               Using host libthread_db library "/lib/aarch64-linux-gnu/libthread_db.so.1".                                                                                                                 hi
        map[a:[b c d] e:[f g h]], 99, spongepants                                                                                                                                                   [Inferior 1 (process 1159565) exited normally]
        BEGIN info goroutines
        Traceback (most recent call last):
          File "/usr/local/go/src/runtime/runtime-gdb.py", line 567, in invoke                                                                                                                          for ptr in SliceValue(gdb.parse_and_eval("'runtime.allgs'")):
        gdb.error: 'runtime.allgs' has unknown type; cast it to its declared type
        Error occurred in Python: 'runtime.allgs' has unknown type; cast it to its declared type
        END                                                                                                                                                                                         BEGIN print smallmapvar                                                                                                                                                                     No symbol "smallmapvar" in current context.                                                                                                                                                 END                                                                                                                                                                                         BEGIN print mapvar                                                                                                                                                                          No symbol "mapvar" in current context.                                                                                                                                                      END
        BEGIN print slicemap                                                                                                                                                                        No symbol "slicemap" in current context.
        END
        BEGIN print strvar                                                                                                                                                                          No symbol "strvar" in current context.                                                                                                                                                      END
        BEGIN print chanint                                                                                                                                                                         No symbol "chanint" in current context.
        END
        BEGIN print chanstr
        No symbol "chanstr" in current context.
        END                                                                                                                                                                                         BEGIN info locals
        No frame selected.
        END
        BEGIN goroutine 1 bt
        Traceback (most recent call last):
          File "/usr/local/go/src/runtime/runtime-gdb.py", line 661, in invoke
            self.invoke_per_goid(goid, cmd)
          File "/usr/local/go/src/runtime/runtime-gdb.py", line 664, in invoke_per_goid
            pc, sp = find_goroutine(goid)
          File "/usr/local/go/src/runtime/runtime-gdb.py", line 592, in find_goroutine
            for ptr in SliceValue(gdb.parse_and_eval("'runtime.allgs'")):
        gdb.error: 'runtime.allgs' has unknown type; cast it to its declared type
        Error occurred in Python: 'runtime.allgs' has unknown type; cast it to its declared type
        END
        BEGIN goroutine all bt
        Traceback (most recent call last):
          File "/usr/local/go/src/runtime/runtime-gdb.py", line 655, in invoke
            for ptr in SliceValue(gdb.parse_and_eval("'runtime.allgs'")):
        gdb.error: 'runtime.allgs' has unknown type; cast it to its declared type
        Error occurred in Python: 'runtime.allgs' has unknown type; cast it to its declared type
        END
        No source file named main.go.
        No source file named main.go.
        Make breakpoint pending on future shared library load? (y or [n]) [answered N; input not from terminal]
        The program is not being run.
        BEGIN goroutine 1 bt at the end
        Traceback (most recent call last):
          File "/usr/local/go/src/runtime/runtime-gdb.py", line 661, in invoke
            self.invoke_per_goid(goid, cmd)
          File "/usr/local/go/src/runtime/runtime-gdb.py", line 664, in invoke_per_goid
            pc, sp = find_goroutine(goid)
          File "/usr/local/go/src/runtime/runtime-gdb.py", line 592, in find_goroutine
            for ptr in SliceValue(gdb.parse_and_eval("'runtime.allgs'")):
        gdb.error: 'runtime.allgs' has unknown type; cast it to its declared type
        Error occurred in Python: 'runtime.allgs' has unknown type; cast it to its declared type
        END
    runtime-gdb_test.go:354: info goroutines failed: Traceback (most recent call last):
          File "/usr/local/go/src/runtime/runtime-gdb.py", line 567, in invoke
            for ptr in SliceValue(gdb.parse_and_eval("'runtime.allgs'")):
        gdb.error: 'runtime.allgs' has unknown type; cast it to its declared type
        Error occurred in Python: 'runtime.allgs' has unknown type; cast it to its declared type
FAIL
FAIL    runtime 7.209s
FAIL

What did you expect to see?

Test should pass.

The text was updated successfully, but these errors were encountered:

JunyangShao · 2025-03-07T19:26:09Z

@golang/runtime

mknyszek · 2025-03-12T20:18:39Z

In triage, this seems like a DWARF issue? CC @dr2chase @thanm

CC @golang/compiler

go-delve/delve#3873 seems related, and this might end up being a Clang problem.

thanm · 2025-03-12T21:53:46Z

@linsite for what it's worth we have a builder that runs clang-15 on linux/arm64 on every commit, and we don't see these failures there. This says to me that the test is failing on your particular system due to some sort of configuration problem, most likely with clang or GDB, not with Go. It's hard to think of possible suggestions without being able to experiment with the system by hand.

Generally speaking this error ("gdb.error: 'runtime.allgs' has unknown type; cast it to its declared type") means that GDB was able to start up the binary but wasn't able to read the Go-specific debug info (DWARF). This can mean that GDB is too old (I note that you did not include the GDB version with your report -- that piece of info would be helpful), or it could be that somehow the compiler is doing something that GDB doesn't like. Thanks.

linsite · 2025-03-13T00:03:22Z

@linsite for what it's worth we have a builder that runs clang-15 on linux/arm64 on every commit, and we don't see these failures there. This says to me that the test is failing on your particular system due to some sort of configuration problem, most likely with clang or GDB, not with Go. It's hard to think of possible suggestions without being able to experiment with the system by hand.

Generally speaking this error ("gdb.error: 'runtime.allgs' has unknown type; cast it to its declared type") means that GDB was able to start up the binary but wasn't able to read the Go-specific debug info (DWARF). This can mean that GDB is too old (I note that you did not include the GDB version with your report -- that piece of info would be helpful), or it could be that somehow the compiler is doing something that GDB doesn't like. Thanks.

gdb info has been added. FYI gcc seems to work fine in the very same environment.

$ CC=/usr/bin/gcc go test runtime -run TestGdbPythonCgo
ok      runtime 8.265s

if there are any tests or information needed, please let me know.
i'll try to do a build manully to see if there is anything intresting.

ianlancetaylor · 2025-03-13T00:17:50Z

gdb 9 is fairly old. On the Go clang15 builder we are running gdb 13.1. Just a couple of days ago we changed the minimum gdb requirement on HEAD to be gdb 10. Perhaps we should simply backport that requirement.

linsite · 2025-03-13T00:42:25Z

Thanks. @ianlancetaylor

It's clear to me now that clang15 is using DWARFv5, is not compatible with gdb 9.

gdb 9 is fairly old. On the Go clang15 builder we are running gdb 13.1. Just a couple of days ago we changed the minimum gdb requirement on HEAD to be gdb 10. Perhaps we should simply backport that requirement.

I totally agree, that surely can help.

gopherbot added the compiler/runtime label Mar 7, 2025

JunyangShao added the NeedsInvestigation label Mar 7, 2025

mknyszek added this to Go Compiler / Runtime Mar 12, 2025

mknyszek changed the title ~~runtime: TestGdbPythonCgo failed with clang-15~~ cmd/compile: TestGdbPythonCgo fails with clang15 due to missing DWARF type information Mar 12, 2025

mknyszek moved this to Todo in Go Compiler / Runtime Mar 12, 2025

mknyszek added this to the Backlog milestone Mar 12, 2025

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

cmd/compile: TestGdbPythonCgo fails with clang15 due to missing DWARF type information #72152

cmd/compile: TestGdbPythonCgo fails with clang15 due to missing DWARF type information #72152

linsite commented Mar 7, 2025 •

edited

Loading

JunyangShao commented Mar 7, 2025

mknyszek commented Mar 12, 2025

thanm commented Mar 12, 2025

linsite commented Mar 13, 2025 •

edited

Loading

ianlancetaylor commented Mar 13, 2025

linsite commented Mar 13, 2025 •

edited

Loading

cmd/compile: TestGdbPythonCgo fails with clang15 due to missing DWARF type information #72152

cmd/compile: TestGdbPythonCgo fails with clang15 due to missing DWARF type information #72152

Comments

linsite commented Mar 7, 2025 • edited Loading

Go version

Output of go env in your module/workspace:

What did you do?

What did you see happen?

What did you expect to see?

JunyangShao commented Mar 7, 2025

mknyszek commented Mar 12, 2025

thanm commented Mar 12, 2025

linsite commented Mar 13, 2025 • edited Loading

ianlancetaylor commented Mar 13, 2025

linsite commented Mar 13, 2025 • edited Loading

linsite commented Mar 7, 2025 •

edited

Loading

Output of `go env` in your module/workspace:

linsite commented Mar 13, 2025 •

edited

Loading

linsite commented Mar 13, 2025 •

edited

Loading