go build crashes

[dvyukov]

> What steps will reproduce the problem?

// test.go
package main
import (
    "flag"
    "fmt"
    "rand"
    "runtime"
    "sort"
)
func main() {
    fmt.Printf("Hello, World!")
}

$go build test.go

> What is the expected output?
The tool either successfully compiles the program or produces a meaningful error message.

> What do you see instead?

panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x0 pc=0x455f80]

goroutine 1 [running]:
runtime.panic(0x669e68, 0xf8401ce7b0)
    /usr/local/google/home/dvyukov/go_select/src/pkg/runtime/proc.c:1406 +0xac
runtime.panicstring(0x82dcb3, 0xf840002570)
    /usr/local/google/home/dvyukov/go_select/src/pkg/runtime/runtime.c:128 +0xa3
runtime.sigpanic()
    /usr/local/google/home/dvyukov/go_select/src/pkg/runtime/thread_linux.c:198 +0x168
go/build.(*Tree).PkgDir(0x0, 0xf8400432c0, 0x0, 0xf8401ad1c0)
    /usr/local/google/home/dvyukov/go_select/src/pkg/go/build/path.go:52 +0xfb
main.(*builder).action(0xf840047000, 0x0, 0xf8401ad1c0, 0x1, 0xf8401ce7a0, ...)
    /usr/local/google/home/dvyukov/go_select/src/cmd/go/build.go:327 +0xb8
main.(*builder).action(0xf840047000, 0x1, 0xf84001ce00, 0x6e69616d00000002,
0xf8401e8b0a, ...)
    /usr/local/google/home/dvyukov/go_select/src/cmd/go/build.go:335 +0x208
main.runBuild(0x82abc0, 0xf840002020, 0x100000001, 0x0)
    /usr/local/google/home/dvyukov/go_select/src/cmd/go/build.go:129 +0x386
main.main()
    /usr/local/google/home/dvyukov/go_select/src/cmd/go/main.go:126 +0x2d8
runtime.main()
    /usr/local/google/home/dvyukov/go_select/src/pkg/runtime/proc.c:231 +0x45
runtime.goexit()
    /usr/local/google/home/dvyukov/go_select/src/pkg/runtime/proc.c:258

>Please use labels and text to provide additional information.
11662:b6e94b31350e tip

[patrickmn]

Comment 1:

This occurs after the error ErrNotFound ("package could not be found locally") occurs in
loadPackage for rand, and is ignored:
...
builder.action -> p is: &{rand      false false true rand:
/home/patrick/temp/test.go:6:2: package could not be found locally [] [] [] [] [] [] []
[] [] [] [] [] <nil>  <nil> [] [] []  false}
builder.action -> p.t is: <nil>
PkgDir -> t is: <nil>
panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x0 pc=0x455f8b]
goroutine 1 [running]:
go/build.(*Tree).PkgDir(0x0, 0x200000002, 0xe, 0x0)
    /home/patrick/apps/go-wk/src/pkg/go/build/path.go:54 +0x292
main.(*builder).action(0xf840049000, 0x0, 0xf84019a1c0, 0x1, 0xf840091160, ...)
    /home/patrick/apps/go-wk/src/cmd/go/build.go:330 +0x241
main.(*builder).action(0xf840049000, 0x1, 0xf84001d540, 0x6e69616d00000002,
0xf8401c3daa, ...)
    /home/patrick/apps/go-wk/src/cmd/go/build.go:338 +0x39a
main.runBuild(0x829b70, 0xf840002020, 0x100000001, 0x0)
    /home/patrick/apps/go-wk/src/cmd/go/build.go:129 +0x386
main.main()
    /home/patrick/apps/go-wk/src/cmd/go/main.go:126 +0x2d8

[kylelemons]

Comment 2:

I believe this is a duplicate of issue #2865?  I have a CL out that will fix it if so.
http://golang.org/cl/5624052/

[dvyukov]

Comment 3:

Status changed to Duplicate.

Merged into issue #2865.