panic: in loadDebugInfoMapsCompileUnit: interface {} is nil, not dwarf.Offset

[tbg]

Delve Debugger
Version: 1.2.0
Build: $Id: 068e2451004e95d0b042e5257e34f0f08ce01466 $
go version go1.12.7 linux/amd64
lsb_release -a
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 16.04.3 LTS
Release:	16.04
Codename:	xenial

(this is an instance on AWS)

Trying to attach to a cockroach process:

$ dlv attach 24490
panic: interface conversion: interface {} is nil, not dwarf.Offset

goroutine 13 [running]:
github.com/go-delve/delve/pkg/proc.(*BinaryInfo).loadDebugInfoMapsCompileUnit(0xc000001800, 0xc0000c60e0, 0xc0000fe6e0, 0xc0000ac480, 0xc0147b5950)
	/home/ubuntu/go/src/github.com/go-delve/delve/pkg/proc/types.go:414 +0x1861
github.com/go-delve/delve/pkg/proc.(*BinaryInfo).loadDebugInfoMaps(0xc000001800, 0xc0000fe6e0, 0xc0069fc000, 0xcb4b4b, 0xcb4b4b, 0xc0000b6bb0, 0x0)
	/home/ubuntu/go/src/github.com/go-delve/delve/pkg/proc/types.go:267 +0x591
created by github.com/go-delve/delve/pkg/proc.loadBinaryInfoElf
	/home/ubuntu/go/src/github.com/go-delve/delve/pkg/proc/bininfo.go:904 +0x3d5

Hopefully repros for others via this binary: https://drive.google.com/file/d/1-CkILyxXwzjTBLIvzCJ21-ud6vuBHs6w/view?usp=sharing (definitely repros here)

dlv exec ./cockroach.boom version

I worked around this via the following diff:

diff --git a/pkg/proc/types.go b/pkg/proc/types.go
index b560d29..017ebc8 100644
--- a/pkg/proc/types.go
+++ b/pkg/proc/types.go
@@ -411,7 +411,8 @@ func (bi *BinaryInfo) loadDebugInfoMapsCompileUnit(ctxt *loadDebugInfoMapsContex
                                                break
                                        }
                                        if entry.Tag == dwarf.TagInlinedSubroutine {
-                                               originOffset := entry.Val(dwarf.AttrAbstractOrigin).(dwarf.Offset)
+                                               originOffset, ok := entry.Val(dwarf.AttrAbstractOrigin).(dwarf.Offset)
+                                               if ok {
                                                name := ctxt.abstractOriginNameTable[originOffset]
                                                if ranges, _ := image.dwarf.Ranges(entry); len(ranges) == 1 {
                                                        ok1 = true
@@ -431,6 +432,9 @@ func (bi *BinaryInfo) loadDebugInfoMapsCompileUnit(ctxt *loadDebugInfoMapsContex
                                                                Parent:   &fn,
                                                        })
                                                }
+                                               } else {
+                                                       fmt.Println("would've crashed")
+                                               }
                                        }
                                        reader.SkipChildren()
                                }

and was able to use dlv normally. (It printed the message dozens of times during startup).

As an additional clue, the issue does not occur with a binary that I thought would be similar:

https://binaries.cockroachdb.com/cockroach-v19.2.0-alpha.20190701.linux-amd64.tgz

[aarzilli]

Thank you for providing a binary.