> In Docker 1.13, the managed plugin api changed, as compared to the experimental version introduced in Docker 1.12. You must **uninstall** plugins which you installed with Docker 1.12 _before_ upgrading to Docker 1.13. You can uninstall plugins using the `docker plugin rm` command.
If you have already upgraded to Docker 1.13 without uninstalling
previously-installed plugins, you may see this message when the Docker daemon
starts:
Error starting daemon: json: cannot unmarshal string into Go value of type types.PluginEnv
To manually remove all plugins and resolve this problem, take the following steps:
1. Remove plugins.json from: `/var/lib/docker/plugins/`.
2. Restart Docker. Verify that the Docker daemon starts with no errors.
3. Reinstall your plugins.
### Builder
+ Add capability to specify images used as a cache source on build. These images do not need to have local parent chain and can be pulled from other registries [#26839](https://github.com/docker/docker/pull/26839)
+ (experimental) Add option to squash image layers to the FROM image after successful builds [#22641](https://github.com/docker/docker/pull/22641)
* Fix dockerfile parser with empty line after escape [#24725](https://github.com/docker/docker/pull/24725)
- Add step number on `docker build` [#24978](https://github.com/docker/docker/pull/24978)
+ Add support for compressing build context during image build [#25837](https://github.com/docker/docker/pull/25837)
+ add `--network` to `docker build` [#27702](https://github.com/docker/docker/pull/27702)
- Fix inconsistent behavior between `--label` flag on `docker build` and `docker run` [#26027](https://github.com/docker/docker/issues/26027)
- Fix image layer inconsistencies when using the overlay storage driver [#27209](https://github.com/docker/docker/pull/27209)
* Unused build-args are now allowed. A warning is presented instead of an error and failed build [#27412](https://github.com/docker/docker/pull/27412)
- Fix builder cache issue on Windows [#27805](https://github.com/docker/docker/pull/27805)
+ Allow `USER` in builder on Windows [#28415](https://github.com/docker/docker/pull/28415)
+ Handle env case-insensitive on Windows [#28725](https://github.com/docker/docker/pull/28725)
### Contrib
+ Add support for building docker debs for Ubuntu 16.04 Xenial on PPC64LE [#23438](https://github.com/docker/docker/pull/23438)
+ Add support for building docker debs for Ubuntu 16.04 Xenial on s390x [#26104](https://github.com/docker/docker/pull/26104)
+ Add support for building docker debs for Ubuntu 16.10 Yakkety Yak on PPC64LE [#28046](https://github.com/docker/docker/pull/28046)
- Add RPM builder for VMWare Photon OS [#24116](https://github.com/docker/docker/pull/24116)
+ Add shell completions to tgz [#27735](https://github.com/docker/docker/pull/27735)
* Update the install script to allow using the mirror in China [#27005](https://github.com/docker/docker/pull/27005)
+ Add DEB builder for Ubuntu 16.10 Yakkety Yak [#27993](https://github.com/docker/docker/pull/27993)
+ Add RPM builder for Fedora 25 [#28222](https://github.com/docker/docker/pull/28222)
+ Add `make deb` support for aarch64 [#27625](https://github.com/docker/docker/pull/27625)
### Distribution
* Update notary dependency to 0.4.2 (full changelogs [here](https://github.com/docker/notary/releases/tag/v0.4.2)) [#27074](https://github.com/docker/docker/pull/27074)
- Support for compilation on windows [docker/notary#970](https://github.com/docker/notary/pull/970)
- Improved error messages for client authentication errors [docker/notary#972](https://github.com/docker/notary/pull/972)
- Support for finding keys that are anywhere in the `~/.docker/trust/private` directory, not just under `~/.docker/trust/private/root_keys` or `~/.docker/trust/private/tuf_keys` [docker/notary#981](https://github.com/docker/notary/pull/981)
- Previously, on any error updating, the client would fall back on the cache. Now we only do so if there is a network error or if the server is unavailable or missing the TUF data. Invalid TUF data will cause the update to fail - for example if there was an invalid root rotation. [docker/notary#982](https://github.com/docker/notary/pull/982)