Hm, interesting. I'm going to try it and see how much bloat it adds.

I think we pull in dynamic libraries through C dependencies:

$ go build .
$ ldd ./cipd
	linux-vdso.so.1 =>  (0x00007ffd0a904000)
	libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f8c75761000)
	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f8c75398000)
	/lib64/ld-linux-x86-64.so.2 (0x00007f8c7597f000)

$ CGO_ENABLED=0 go build .
$ ldd ./cipd
	not a dynamic executable

We already quite heavily rely on non-cgo builds when cross-compiling. I think it would be OK to disable cgo even when not cross-compiling. It would make all our binaries statically linked.

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/1599153bc5487c96bf66c74c187d67fd3ea5a3f1

commit 1599153bc5487c96bf66c74c187d67fd3ea5a3f1
Author: Vadim Shtayura <vadimsh@chromium.org>
Date: Tue Dec 19 22:28:35 2017

Disable cgo on Linux and Windows.

There are multiple reasons for this:
 * Makes all binaries statically linked (no dependency on dynamic libc).
 * Makes cross-compiled and non-cross-compiled binaries be more similar, so
   they behave uniformly across platforms.
 * Makes sure dependencies with cgo don't work locally for developers, as
   they won't really work when building code on the bots. We don't maintain
   C toolchain on bots that build Go code currently (especially true for
   Windows bots).

Unfortunately, some third party libraries (e.g github.com/shirou/gopsutil)
have poor support for non-cgo build on OSX, so we keep it enabled on OSX,
assuming there's not a wide variety of OSX platforms out there and it's fine
to have dynamically linked binaries.

R=iannucci@chromium.org
BUG= 796320 

Change-Id: Ie947e716375cb4af3f17169bd30823de2470b9f8
Reviewed-on: https://chromium-review.googlesource.com/834992
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Commit-Queue: Vadim Shtayura <vadimsh@chromium.org>

[modify] https://crrev.com/1599153bc5487c96bf66c74c187d67fd3ea5a3f1/go/bootstrap.py

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/ac945475528762bd6e91a865919990a5a393503a

commit ac945475528762bd6e91a865919990a5a393503a
Author: Vadim Shtayura <vadimsh@chromium.org>
Date: Tue Dec 19 23:12:16 2017

Revert "Disable cgo on Linux and Windows."

This reverts commit 1599153bc5487c96bf66c74c187d67fd3ea5a3f1.

Reason for revert: 'go test -race' needs cgo :(

Original change's description:
> Disable cgo on Linux and Windows.
> 
> There are multiple reasons for this:
>  * Makes all binaries statically linked (no dependency on dynamic libc).
>  * Makes cross-compiled and non-cross-compiled binaries be more similar, so
>    they behave uniformly across platforms.
>  * Makes sure dependencies with cgo don't work locally for developers, as
>    they won't really work when building code on the bots. We don't maintain
>    C toolchain on bots that build Go code currently (especially true for
>    Windows bots).
> 
> Unfortunately, some third party libraries (e.g github.com/shirou/gopsutil)
> have poor support for non-cgo build on OSX, so we keep it enabled on OSX,
> assuming there's not a wide variety of OSX platforms out there and it's fine
> to have dynamically linked binaries.
> 
> R=​iannucci@chromium.org
> BUG= 796320 
> 
> Change-Id: Ie947e716375cb4af3f17169bd30823de2470b9f8
> Reviewed-on: https://chromium-review.googlesource.com/834992
> Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
> Commit-Queue: Vadim Shtayura <vadimsh@chromium.org>

TBR=iannucci@chromium.org,vadimsh@chromium.org

Change-Id: I5614fc4809ae025503136109c6eb8ac58d59e415
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug:  796320 
Reviewed-on: https://chromium-review.googlesource.com/834671
Reviewed-by: Vadim Shtayura <vadimsh@chromium.org>
Commit-Queue: Vadim Shtayura <vadimsh@chromium.org>

[modify] https://crrev.com/ac945475528762bd6e91a865919990a5a393503a/go/bootstrap.py

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/2288f0cb47eea8b5430882867099586afcee2368

commit 2288f0cb47eea8b5430882867099586afcee2368
Author: Vadim Shtayura <vadimsh@chromium.org>
Date: Wed Dec 20 04:38:05 2017

Selectively build some CIPD packages with CGO_ENABLED=0.

This makes them statically linked.

We don't build all packages that way because our CI system uses cgo-enabled
binaries by default, and testing a cgo-enabled variant of a package but
releasing a non-cgo one (by default) is not very smart (though we do it
currently when cross-compiling, unfortunately).

Instead owners of the package should decide whether its OK to release non-cgo
variant or not by modifying corresponding package definition YAML.

R=iannucci@chromium.org
BUG= 796320 

Change-Id: Ie6fbb5bf77fa1d387eee3fbc8e6ec0d4c1391d4d
Reviewed-on: https://chromium-review.googlesource.com/835871
Commit-Queue: Vadim Shtayura <vadimsh@chromium.org>
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>

[modify] https://crrev.com/2288f0cb47eea8b5430882867099586afcee2368/build/README.md
[modify] https://crrev.com/2288f0cb47eea8b5430882867099586afcee2368/build/packages/cipd_client.yaml
[modify] https://crrev.com/2288f0cb47eea8b5430882867099586afcee2368/build/build.py
[modify] https://crrev.com/2288f0cb47eea8b5430882867099586afcee2368/build/packages/vpython-native.yaml
[modify] https://crrev.com/2288f0cb47eea8b5430882867099586afcee2368/build/packages/led.yaml
[modify] https://crrev.com/2288f0cb47eea8b5430882867099586afcee2368/build/packages/vpython.yaml

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/tools/depot_tools/+/9b5cb92fa457c8f61a058c6584c3bec233088c3b

commit 9b5cb92fa457c8f61a058c6584c3bec233088c3b
Author: Vadim Shtayura <vadimsh@chromium.org>
Date: Wed Dec 20 19:41:02 2017

Update cipd client version.

Notable changes here:
 * 'cipd' binary is now statically linked and doesn't depend of libc.so.
 * New 'cipd instances <pkg>' subcommand that list recently uploaded instances
   of a package.
 * cipd now properly removes empty directory trees if they are left after
   uninstalling some files.

R=iannucci@chromium.org
BUG= 796320 ,  789750 

Change-Id: Iebc5655640defbbef4a5fb1850aeb852746e5ef3
Reviewed-on: https://chromium-review.googlesource.com/835657
Commit-Queue: Vadim Shtayura <vadimsh@chromium.org>
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>

[modify] https://crrev.com/9b5cb92fa457c8f61a058c6584c3bec233088c3b/cipd_client_version

Assigning to Vadim since he worked on it.

All Go binaries in depot_tools (cipd and vpython specifically) are statically linked now.