cmd/go: working dir for link changed between Go 1.0.3 and Go 1.1

[gopherbot]

by cgmurray:

What steps will reproduce the problem?
run "go test -x ROOT_PACKAGE/..." with go 1.0.3 and tip (13e00572ed0b)

What is the expected output?
working directory is changed for every package with go 1.1, "cd ... or
equivalent"

What do you see instead?
working directory is not changed for every package as with go 1.0.3

Which compiler are you using (5g, 6g, 8g, gccgo)?
-

Which operating system are you using?
osx

Which version are you using?  (run 'go version')
go version devel +13e00572ed0b Thu Apr 18 17:37:21 2013 -0700 darwin/amd64

Please provide any additional information below.
This might break backwards compatibility. In the specific use-case a relative
library-path is set with -L

[minux]

Comment 1:

are you sure about this?
In my test, there is a "cd package_dir" before the build commands.
please provide the output of "go test -x ROOT_PACKAGE/...", or
perhaps write a example using relative library with -L to
demonstrate the problem?

Status changed to WaitingForReply.

[gopherbot]

Comment 2 by cgmurray:

I actually missed the cd commands but the symptom is similar. A self-contained
bash-script to demonstrate the problem is attached.

Attachments:

1. issue5319.bash (491 bytes)

[minux]

Comment 3:

the problem is that we never supported put a relative path reference
to an object file in CGO_LDFLAGS. Because when the package is actually
used, the relative path is guaranteed to be incorrect.
if you change p.go to actually invoke C.F() and p_test.go to actually
invoke F(), you will see go 1.0.3 couldn't handle this either.

[gopherbot]

Comment 4 by cgmurray:

I understand but my example was a bit contrived. I my real case I link to a shared
library. An updated version of the script attached. Note that it's written for osx. In
order to run it on linux "gcc -dynamiclib" must be replaced with "gcc -shared" and
"export DYLD_LIBRARY_PATH=..." with "export LD_LIBRARY_PATH=..."
Is relative library paths supported in go 1.x?

Attachments:

1. issue5319.bash (593 bytes)

[gopherbot]

Comment 5 by cgmurray:

Forgot to mention that libissue5319.dylib must be replaced with libissue5319.so on linux.

[minux]

Comment 6:

you could embed rpath into the executable by adding -Wl,-rpath,PATH to
CGO_LDFLAGS, but bear in mind that PATH could need to be absolute.
ps: take a look at $GOROOT/misc/cgo/testso.

[gopherbot]

Comment 7 by cgmurray:

Do we agree on that the behaviour has changed between go 1.0.3 and tip? The latest
scripts works with 1.0.3 but not with tip.

[rsc]

Comment 8:

FWIW, I have not confirmed the report, and I am not sure it is something we need to fix
regardless.

Labels changed: added priority-later, go1.2maybe, removed priority-triage.

Status changed to Accepted.

[rsc]

Comment 9:

Labels changed: added feature.

[robpike]

Comment 10:

Unclear. Deferring to 1.3

Labels changed: added go1.3maybe, removed go1.2maybe.

[robpike]

Comment 11:

Labels changed: removed go1.3maybe.

[rsc]

Comment 12:

I'd like to at least understand this better before we cut Go 1.2. We may not change
anything.

Labels changed: added go1.2maybe, removed feature.

[rsc]

Comment 13:

Status changed to Duplicate.

Merged into issue #5428.