delve: On macOS a SIGSEGV (EXC_BAD_ACCESS) can not be propagated back to the target

What version of Delve are you using (dlv version)? Version: 1.0.0-rc.1
What version of Go are you using? (go version)? go version go1.8.2 darwin/amd64 note: also occurs with 1.8.1
What operating system and processor architecture are you using? OSX El Capitan
What did you do? Attempt to debug go program that uses go-kit/kit/log
What did you expect to see? Program runs normally
What did you see instead? Program stops at go-stack/stack/stack.go/stack.go:228

Here is the source code:

package main

import (
	"os"
	"github.com/go-kit/kit/log"
)

func main() {
	log.NewLogfmtLogger(os.Stdout)
}

Here’s what the delve session looks like:

~/dev/go/src/mat/foo $ dlv debug
Type 'help' for list of commands.
(dlv) continue
> mat/vendor/github.com/go-stack/stack.findSigpanic.func1() /Users/mathewnelson/dev/go/src/mat/vendor/github.com/go-stack/stack/stack.go:228 (PC: 0x10b8ec3)
   223:						}
   224:					}
   225:				}
   226:			}()
   227:			// intentional nil pointer dereference to trigger sigpanic
=> 228:			return *p
   229:		}()
   230:		return fn
   231:	}
   232:	
   233:	var sigpanic = findSigpanic()
(dlv)

This was working with 0.12.2.

Thank you.

About this issue

Original URL
State: closed
Created 7 years ago
Reactions: 12
Comments: 18 (11 by maintainers)

Links to this issue

Testing with go-sqlmock with gorm (help with runtime error)

Commits related to this issue

terminal: print something when continue errors even if we don't have a file We should print something when we exit from continue/next/step/stepout even if we don't have a source file for the instruc... — committed to aarzilli/delve by aarzilli 6 years ago
terminal: print something when continue errors even if we don't have a file We should print something when we exit from continue/next/step/stepout even if we don't have a source file for the instruc... — committed to go-delve/delve by aarzilli 6 years ago
[debugserver] Add option to propagate SIGSEGV to target process Adds a command line option that makes debugserver propagate the SIGSEGV signal to the target process. Motivation: I'm one of the maint... — committed to llvm/llvm-project by aarzilli 4 years ago
[debugserver] Add option to propagate SIGSEGV to target process Adds a command line option that makes debugserver propagate the SIGSEGV signal to the target process. Motivation: I'm one of the maint... — committed to llvm/Polygeist by aarzilli 4 years ago
proc/gdbserial: use --unmask-signal debugserver option Fixes #852 — committed to aarzilli/delve by deleted user 4 years ago
proc/gdbserial: use --unmask-signal debugserver option (#2255) Fixes #852 Co-authored-by: a <a@kra> — committed to go-delve/delve by aarzilli 4 years ago
[debugserver] Add option to propagate SIGSEGV to target process Adds a command line option that makes debugserver propagate the SIGSEGV signal to the target process. Motivation: I'm one of the maint... — committed to arichardson/llvm-project by aarzilli 4 years ago
terminal: print something when continue errors even if we don't have a file We should print something when we exit from continue/next/step/stepout even if we don't have a source file for the instruc... — committed to cgxxv/delve by aarzilli 6 years ago

Most upvoted comments

Is there any workaround for this? This is really a pain.

+14

CermakM on Jul 14, 2020

Note: even though this bug is closed you will continue to experience it until a version of debugserver with the corresponding patch is installed. At the time of this message no released version of xcode command line tools has it.

aarzilli on Dec 11, 2020

Here’s a simple solution on my mac to build debugserver from sourcecode:

git clone https://github.com/llvm/llvm-project.git   // download llvm source code (lldb source code inside)
git checkout llvmorg-12.0.1-rc4 # this version has already supported unmask_signals
brew install cmake # install cmake to build debugserver
cd llvm-project && mkdir zz && cd zz && cmake -DLLVM_ENABLE_PROJECTS="clang;lldb" -DLLDB_INCLUDE_TESTS=OFF   ../llvm #  use cmake to generate Makefile
make debugserver -j16 #  compile debugserver

The last step is to configure go-delve to use debugserver compiled above. Here are some possible solutions:

If your go-delve version is earlier than v1.4.1, the debugserver path is an absolute path in go-delve, you need to either modify go-delve source code or overwrite debugserver binary. https://github.com/go-delve/delve/blob/81a86086dd9974d5bab76b1749d7450bb6b5cfab/pkg/proc/gdbserial/gdbserver.go#L300
If your go-delve is v1.4.1 or later versions, then you can override environment variable PATH like

export PATH=${direcotry_path_of_newly_compiled_debugserver):$PATH

If your go-delve is v1.6.1, you can set environment variable DELVE_DEBUGSERVER_PATH, dlv will use the value of this variable as the absolute path of debugserver.

staugust on Jul 13, 2021

I haven’t experienced this since upgrading to Go 1.15.4 🤞 I think https://github.com/golang/go/commit/1b49a86ecece3978ceba60c372327b9cbcc68501 may provide the workaround

Building the lldb debug server manually wasn’t straightforward or easy 😞

daxmc99 on Nov 11, 2020