gb fails when pwd has a symlink

[eparis]

Below is a reproducer script. You will see gb build work once and fail once. The second time it looks like gb is figuring out the absolute/real path of cwd and then doing ../../../ type operations in relation to the absolute path. But linux is obviously interpreting those in relation to pwd....

#!/bin/bash
set -e

export GOPATH="$HOME/gopath"

# The following should work just fine.
go get k8s.io/kubernetes
cd $GOPATH/src/k8s.io/kubernetes
mkdir -p _output/local/go/src/k8s.io
ln -s $GOPATH/src/k8s.io/kubernetes _output/local/go/src/k8s.io/kubernetes > /dev/null 2>&1 || true
ln -s $GOPATH/src/k8s.io/kubernetes/Godeps/_workspace/ _output/local/go/vendor > /dev/null 2>&1 || true

echo "Setup complete. Now to run the test where pwd does not have a symlink"

# you must explicitly tell it what to build as filepath.Walk() will not follow the src/k8s.io/kubernetes symlink  :-(
cd $GOPATH/src/k8s.io/kubernetes/_output/local/go
gb build k8s.io/kubernetes/cmd/kubelet

echo "YAY! It worked! (I knew it would), now watch it fail because pwd does have a symlink!!!"

# But this will not work  :-(
ln -s $GOPATH/src/k8s.io/kubernetes $HOME/kubernetes > /dev/null 2>&1 || true
cd $HOME/kubernetes/_output/local/go/
gb build k8s.io/kubernetes/cmd/kubelet

[davecheney]

@eparis I'm really sorry but gb takes the same position on symlinks that the go tool does. Symlinks are not support inside src/ directories because they permit the same source to appear more than once in the tree.

I know this isn't the whole of this issue report, but I wanted to my position on symlinks clear to set your expectations appropriately.

[eparis]

I found/know that symlink issue as well. I really wanted a filepath.WalkFollowLinks() but I understand. But you're right, that's not this bug report.

In this case the problem is the symlink in pwd not in/below src. If I cd to the exact same pwd using the realpath everything works just fine.

You're right, I also have a symlink under src/ which means I can't just use gb build I have to use gb build k8s.io/kubernetes/cmd/kubelet.

I know the reproducer is kind of a pain to understand. I can do something a little cleaner/easier if you like/need, that's just obviously exactly the case I hit trying to convert kubernetes to use gb

[thockin]

It's not helpful because @eparis and I are trying to achieve the same goal on the same project, but I want to be on record that this position on symlinks is, IMO, wrong. If you want to crash my computer in case of a symlink loop or turn on my webcam when I make the same source appear twice in a tree (why is that bad, really?) go right ahead.

But this is inhibiting my ability to Get Things Done. I want to use gb and I can't do what I need to transition to it.

[thockin]

Any thoughts on progress on this?

[davecheney]

I'm sorry I have not had a chance to investigate this.

On Sun, Nov 22, 2015 at 7:13 AM, Tim Hockin notifications@github.com
wrote:

Any thoughts on progress on this?

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Reply to this email directly or view it on GitHub
#308 (comment).

[davecheney]

@eparis @thockin I think #483 might improve the situation.

[thockin]

From a kubernetes repo:

    rm -rf _gb  #FIXME:remove
    mkdir -p _output/local/go/{bin,pkg}
    mkdir -p _gb/src/k8s.io
    ln -s ../../../ _gb/src/k8s.io/kubernetes
    ln -s ../Godeps/_workspace/ _gb/vendor
    ln -s ../_output/local/go/bin _gb/bin
    ln -s ../_output/local/go/pkg _gb/pkg
    gb build -R _gb k8s.io/kubernetes/cmd/kube-proxy  # works
    gb build -R _gb k8s.io/kubernetes/cmd/...  # FATAL: command "build" failed: no packages supplied
    gb build -R _gb ./...  # FATAL: command "build" failed: no packages supplied

Still no love.

[eparis]

I think this does fix my bug, where gb went off the rails when pwd had a symlink.

But agree with Tim that isn't a huge pain that pathwalk has absolutely no 'follow symlinks' option. So go won't find packages via ./...

[davecheney]

I'm sorry but I don't think I can support that syntax, that places a
symlink inside the $PROJECT/src.

On Tue, Dec 15, 2015 at 4:04 AM, Tim Hockin notifications@github.com
wrote:

From a kubernetes repo:

rm -rf _gb  #FIXME:remove
mkdir -p _output/local/go/{bin,pkg}
mkdir -p _gb/src/k8s.io
ln -s ../../../ _gb/src/k8s.io/kubernetes
ln -s ../Godeps/_workspace/ _gb/vendor
ln -s ../_output/local/go/bin _gb/bin
ln -s ../_output/local/go/pkg _gb/pkg
gb build -R _gb k8s.io/kubernetes/cmd/kube-proxy  # works
gb build -R _gb k8s.io/kubernetes/cmd/...  # FATAL: command "build" failed: no packages supplied
gb build -R _gb ./...  # FATAL: command "build" failed: no packages supplied

Still no love.

—
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#308 (comment).

[thockin]

I don't understand the hate on symlinks? It's inane to me that the code
layout is dictated to be laid out JUST SO and yet I can't massage my way
around it?

On Mon, Dec 14, 2015 at 4:31 PM, Dave Cheney notifications@github.com
wrote:

I'm sorry but I don't think I can support that syntax, that places a
symlink inside the $PROJECT/src.

On Tue, Dec 15, 2015 at 4:04 AM, Tim Hockin notifications@github.com
wrote:

From a kubernetes repo:

rm -rf _gb #FIXME:remove
mkdir -p _output/local/go/{bin,pkg}
mkdir -p _gb/src/k8s.io
ln -s ../../../ _gb/src/k8s.io/kubernetes
ln -s ../Godeps/_workspace/ _gb/vendor
ln -s ../_output/local/go/bin _gb/bin
ln -s ../_output/local/go/pkg _gb/pkg
gb build -R _gb k8s.io/kubernetes/cmd/kube-proxy # works
gb build -R _gb k8s.io/kubernetes/cmd/... # FATAL: command "build"
failed: no packages supplied
gb build -R _gb ./... # FATAL: command "build" failed: no packages
supplied

Still no love.

—
Reply to this email directly or view it on GitHub
#308 (comment).

—
Reply to this email directly or view it on GitHub
#308 (comment).