cmd/go: running dsymutil failed: signal: segmentation fault

[kevinburke]

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

go version devel +38083c83a6 Thu Dec 7 23:37:46 2017 +0000 darwin/amd64

Does this issue reproduce with the latest release?

No

What operating system and processor architecture are you using (go env)?

GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/kevin/Library/Caches/go-build"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/kevin"
GORACE=""
GOROOT="/Users/kevin/go"
GOTMPDIR=""
GOTOOLDIR="/Users/kevin/go/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-build854984327=/tmp/go-build -gno-record-gcc-switches -fno-common"

Mac Sierra version 10.12.6. Using confluentinc/confluent-kafka-go@99a5add.

What did you do?

I tried to compile a program that uses confluent-kafka-go and makes HTTP requests. Unfortunately it's proprietary, but I can answer questions about it if need be.

I frequently recompile Go tip with the latest commit.

The compilation argument was:

go install -v -race ./...

What did you expect to see?

I expected the program to compile.

What did you see instead?

This error message (and only this error message):

$ go install -v -race ./...
# github.com/proprietary/proprietary/cmd/program
/Users/kevin/go/pkg/tool/darwin_amd64/link: /Users/kevin/go/pkg/tool/darwin_amd64/link: running dsymutil failed: signal: segmentation fault

I can blow away my cache if need be, or try a different commit, but I'm completely in the dark about how to trigger this, and worried that if I make changes (like e.g. blowing away the cache) I won't be able to reliably reproduce the problem.

Running on my high end Macbook Pro which should have enough memory, CPU etc.

[bradfitz]

Back up your cache first, or rename it away to $GOPATH/pkg/obj => $GOPATH/pkg/obj.old first?

Also, add -x to go install?

[heschi]

This is kind of annoying to debug. From memory: Run go install -x -work -ldflags=-v. That should print, and preserve, the working directory. Then run dsymutil --verbose /path/to/binary, which should be close enough to what the linker is doing to reproduce any problems.

(I vaguely remember the binary ending up in a different directory than $WORKDIR that gets deleted unconditionally. In that case you might have to repeat the external link command, which will have been printed, to get a binary to run dsymutil on.)

We'll probably need a dwarfdump too, but let's see if the error messages are obvious without it.

[kevinburke]

The first command you gave me - go install -x -work - failed with a segfault. Here's the last bit of it

HEADER = -H1 -T0x1001000 -D0x0 -R0x1000
 0.00 deadcode
 0.05 pclntab=1509285 bytes, funcdata total 266158 bytes
 0.06 dodata
 0.07 symsize = 0
 0.08 symsize = 0
 0.09 dynreloc
 0.10 dwarf
 0.12 symsize = 0
 0.18 reloc
 0.20 asmb
 0.20 codeblk
 0.22 datblk
 0.24 sym
 0.25 headr
 0.31 host link: "clang" "-m64" "-Wl,-headerpad,1144" "-Wl,-no_pie" "-Wl,-pagezero_size,4000000" "-o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-build795571505/b001/exe/a.out" "-Qunused-arguments" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/go.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000000.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000001.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000002.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000003.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000004.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000005.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000006.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000007.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000008.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000009.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000010.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000011.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000012.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000013.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000014.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000015.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000016.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000017.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000018.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000019.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000020.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000021.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000022.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000023.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000024.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000025.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000026.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000027.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000028.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000029.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000030.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000031.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000032.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000033.o" "/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-216547337/000034.o" "-g" "-O2" "-lrdkafka" "-L/usr/local/Cellar/librdkafka/0.11.3/lib" "-lrdkafka" "-g" "-O2" "-framework" "CoreFoundation" "-framework" "Security" "-g" "-O2" "-g" "-O2" "-lpthread" "-g" "-O2" "-nopie"
/Users/kevin/go/pkg/tool/darwin_amd64/link: /Users/kevin/go/pkg/tool/darwin_amd64/link: running dsymutil failed: signal: segmentation fault

[heschi]

Right, that's expected. The linker ran dsymutil and it crashed; now we need to rerun it with logging so we know why. If /var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-build795571505/b001/exe/a.out still exists, run dsymutil --verbose on it. If not, run the whole clang command (change -o to put a.out in some random directory, doesn't matter) to recreate a.out and then you can dsymutil it.

[kevinburke]

Apologies, you're going to have to walk me through more steps. I'm running the whole clang command and getting an error that looks like this:

clang: error: no such file or directory: '/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-018471642/go.o'
clang: error: no such file or directory: '/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-018471642/000000.o'
clang: error: no such file or directory: '/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-018471642/000001.o'
clang: error: no such file or directory: '/var/folders/sf/fsn3_vgd0n98r0jb86bgp83r0000gn/T/go-link-018471642/000002.o'

And about 30 more.

I'm running this Go command to get the clang command.

go install -x -work -ldflags=-v .

[heschi]

Ugh. I must be forgetting a step or three, sorry. I'll look tomorrow when I can borrow a Mac.

[aarzilli]

Perhaps unsurprisingly this bisects to 4435fcf. If you want a way to reproduce it, building delve (go build github.com/derekparker/delve/cmd/dlv) does it.

[aarzilli]

Output of dsymutil --verbose https://gist.githubusercontent.com/anonymous/7de990e54232b02b350a41e8ee42c255/raw/c1382bd734b41cde490479675d54e3a38f3b9d22/verboseout.txt (I can't find anything useful in it).

[randall77]

@thanm

[thanm]

Ouch. I will take a look.

[aarzilli]

To anybody getting here through a google search, the emergency workaround is stripping the executable -ldflags=-s.