explain how to install beta version of the test runner

source/guides/getting-started/installing-cypress.md

@@ -288,3 +288,62 @@ CYPRESS_DOWNLOAD_MIRROR="https://www.example.com" cypress install
 ```
 
 Cypress will then attempt to download a binary with this format: `https://www.example.com/desktop/:version?platform=p`
+
+## Install pre-release version
+
+In very rare cases you might want to install the pre-release version of Cypress to verify a fix from the {% url "`develop`" https://github.com/cypress-io/cypress/commits/develop %} branch, that has not been published yet.  
+
+{% note info %}
+You can preview all issues addressed from a pre-release version {% url "here" https://github.com/cypress-io/cypress/issues?utf8=%E2%9C%93&q=label%3A%22stage%3A+pending+release%22+ %}.
+{% endnote %}
+
+We build every commit in the {% url "`develop`" https://github.com/cypress-io/cypress/commits/develop %} branch for each platform and test it against downstream projects. For example, in the image below the last commit has the short SHA `e5106d9`.
+
+{% imgTag /img/guides/install/last-commit.png "Last commit on develop branch" %}
+
+The simplest way to find the pre-release version of the Test Runner matching this commit is to look at the commits made on our projects under test at {% url "cypress-test-example-repos" https://github.com/cypress-io/cypress-test-example-repos/commits/master %}. You will see individual commits for each built platform and architecture: `darwin` (Mac), `linux`, `win 32bit` and `win 64bit`. The built commit SHA `e5106d9` is in the subject line of the test commit:
+
+{% imgTag /img/guides/install/test-commits.png "Test commit per platform" %}
+
+These pre-release builds are platform-specific. Choose the platform that matches your platform; for example if you are on a Mac, click on the commit "Testing new darwin x64 ...". This commit has a custom message that shows a special temporary URL of the built binary for Mac OS and the matching npm `cypress` package.
+
+{% imgTag /img/guides/install/beta-binary.png "Beta binary information" %}
+
+To install this pre-release binary on Mac, you need to set the `CYPRESS_INSTALL_BINARY` environment variable to the shown `https://cdn.cypress.io/beta/binary/.../cypress.zip` value and run `npm install https://cdn.cypress.io/beta/npm/3.3.2/.../cypress.tgz`. The command in the terminal will be:
+
+```shell
+export CYPRESS_INSTALL_BINARY=https://cdn.cypress.io/beta/binary/3.3.2/darwin-x64/circle-develop-e5106d95f51eec477b8e66609939979fb87aab56-126014/cypress.zip
+```
+
+```shell
+npm install https://cdn.cypress.io/beta/npm/3.3.2/circle-develop-e5106d95f51eec477b8e66609939979fb87aab56-126013/cypress.tgz
+```
+
+If my machine is Windows 64bit, I will click on the "Testing new win32 x64 ..." commit and run the command below.
+
+```shell
+set CYPRESS_INSTALL_BINARY=https://cdn.cypress.io/beta/binary/3.3.2/win32-x64/appveyor-develop-e5106d95f51eec477b8e66609939979fb87aab56-25451270/cypress.zip
+```
+
+```shell
+npm install https://cdn.cypress.io/beta/npm/3.3.2/appveyor-develop-e5106d95f51eec477b8e66609939979fb87aab56-25451270/cypress.tgz
+```
+
+On Linux CI you should install the binary from the "Testing new linux x64 ..." commit.
+
+```shell
+export CYPRESS_INSTALL_BINARY=https://cdn.cypress.io/beta/binary/3.3.2/linux-x64/circle-develop-e5106d95f51eec477b8e66609939979fb87aab56-125973/cypress.zip
+```
+
+```shell
+npm install https://cdn.cypress.io/beta/npm/3.3.2/circle-develop-e5106d95f51eec477b8e66609939979fb87aab56-125992/cypress.tgz
+```
+
+### Pre-release binary URL format
+
+The above `CYPRESS_INSTALL_BINARY` urls are temporary - they are purged after 30 days. The format of the url is as follows:
+
+```text
+https://cdn.cypress.io/beta/binary/<version>/<platform>-<arch>/
+<ci name>-<branch name>-<full commit SHA>-<CI build number>/cypress.zip
+```

source/ja/guides/getting-started/installing-cypress.md

@@ -279,3 +279,62 @@ CYPRESS_DOWNLOAD_MIRROR="https://www.example.com" cypress install
 ```
 
 Cypress will then attempt to download a binary with this format: `https://www.example.com/desktop/:version?platform=p`
+
+## Install pre-release version
+
+In very rare cases you might want to install the pre-release version of Cypress to verify a fix from the {% url "`develop`" https://github.com/cypress-io/cypress/commits/develop %} branch, that has not been published yet.  
+
+{% note info %}
+You can preview all issues addressed from a pre-release version {% url "here" https://github.com/cypress-io/cypress/issues?utf8=%E2%9C%93&q=label%3A%22stage%3A+pending+release%22+ %}.
+{% endnote %}
+
+We build every commit in the {% url "`develop`" https://github.com/cypress-io/cypress/commits/develop %} branch for each platform and test it against downstream projects. For example, in the image below the last commit has the short SHA `e5106d9`.
+
+{% imgTag /img/guides/install/last-commit.png "Last commit on develop branch" %}
+
+The simplest way to find the pre-release version of the Test Runner matching this commit is to look at the commits made on our projects under test at {% url "cypress-test-example-repos" https://github.com/cypress-io/cypress-test-example-repos/commits/master %}. You will see individual commits for each built platform and architecture: `darwin` (Mac), `linux`, `win 32bit` and `win 64bit`. The built commit SHA `e5106d9` is in the subject line of the test commit:
+
+{% imgTag /img/guides/install/test-commits.png "Test commit per platform" %}
+
+These pre-release builds are platform-specific. Choose the platform that matches your platform; for example if you are on a Mac, click on the commit "Testing new darwin x64 ...". This commit has a custom message that shows a special temporary URL of the built binary for Mac OS and the matching npm `cypress` package.
+
+{% imgTag /img/guides/install/beta-binary.png "Beta binary information" %}
+
+To install this pre-release binary on Mac, you need to set the `CYPRESS_INSTALL_BINARY` environment variable to the shown `https://cdn.cypress.io/beta/binary/.../cypress.zip` value and run `npm install https://cdn.cypress.io/beta/npm/3.3.2/.../cypress.tgz`. The command in the terminal will be:
+
+```shell
+export CYPRESS_INSTALL_BINARY=https://cdn.cypress.io/beta/binary/3.3.2/darwin-x64/circle-develop-e5106d95f51eec477b8e66609939979fb87aab56-126014/cypress.zip
+```
+
+```shell
+npm install https://cdn.cypress.io/beta/npm/3.3.2/circle-develop-e5106d95f51eec477b8e66609939979fb87aab56-126013/cypress.tgz
+```
+
+If my machine is Windows 64bit, I will click on the "Testing new win32 x64 ..." commit and run the command below.
+
+```shell
+set CYPRESS_INSTALL_BINARY=https://cdn.cypress.io/beta/binary/3.3.2/win32-x64/appveyor-develop-e5106d95f51eec477b8e66609939979fb87aab56-25451270/cypress.zip
+```
+
+```shell
+npm install https://cdn.cypress.io/beta/npm/3.3.2/appveyor-develop-e5106d95f51eec477b8e66609939979fb87aab56-25451270/cypress.tgz
+```
+
+On Linux CI you should install the binary from the "Testing new linux x64 ..." commit.
+
+```shell
+export CYPRESS_INSTALL_BINARY=https://cdn.cypress.io/beta/binary/3.3.2/linux-x64/circle-develop-e5106d95f51eec477b8e66609939979fb87aab56-125973/cypress.zip
+```
+
+```shell
+npm install https://cdn.cypress.io/beta/npm/3.3.2/circle-develop-e5106d95f51eec477b8e66609939979fb87aab56-125992/cypress.tgz
+```
+
+### Pre-release binary URL format
+
+The above `CYPRESS_INSTALL_BINARY` urls are temporary - they are purged after 30 days. The format of the url is as follows:
+
+```text
+https://cdn.cypress.io/beta/binary/<version>/<platform>-<arch>/
+<ci name>-<branch name>-<full commit SHA>-<CI build number>/cypress.zip
+```

source/zh-cn/guides/getting-started/installing-cypress.md

@@ -289,3 +289,62 @@ CYPRESS_DOWNLOAD_MIRROR="https://www.example.com" cypress install
 ```
 
 Cypress will then attempt to download a binary with this format: `https://www.example.com/desktop/:version?platform=p`
+
+## Install pre-release version
+
+In very rare cases you might want to install the pre-release version of Cypress to verify a fix from the {% url "`develop`" https://github.com/cypress-io/cypress/commits/develop %} branch, that has not been published yet.  
+
+{% note info %}
+You can preview all issues addressed from a pre-release version {% url "here" https://github.com/cypress-io/cypress/issues?utf8=%E2%9C%93&q=label%3A%22stage%3A+pending+release%22+ %}.
+{% endnote %}
+
+We build every commit in the {% url "`develop`" https://github.com/cypress-io/cypress/commits/develop %} branch for each platform and test it against downstream projects. For example, in the image below the last commit has the short SHA `e5106d9`.
+
+{% imgTag /img/guides/install/last-commit.png "Last commit on develop branch" %}
+
+The simplest way to find the pre-release version of the Test Runner matching this commit is to look at the commits made on our projects under test at {% url "cypress-test-example-repos" https://github.com/cypress-io/cypress-test-example-repos/commits/master %}. You will see individual commits for each built platform and architecture: `darwin` (Mac), `linux`, `win 32bit` and `win 64bit`. The built commit SHA `e5106d9` is in the subject line of the test commit:
+
+{% imgTag /img/guides/install/test-commits.png "Test commit per platform" %}
+
+These pre-release builds are platform-specific. Choose the platform that matches your platform; for example if you are on a Mac, click on the commit "Testing new darwin x64 ...". This commit has a custom message that shows a special temporary URL of the built binary for Mac OS and the matching npm `cypress` package.
+
+{% imgTag /img/guides/install/beta-binary.png "Beta binary information" %}
+
+To install this pre-release binary on Mac, you need to set the `CYPRESS_INSTALL_BINARY` environment variable to the shown `https://cdn.cypress.io/beta/binary/.../cypress.zip` value and run `npm install https://cdn.cypress.io/beta/npm/3.3.2/.../cypress.tgz`. The command in the terminal will be:
+
+```shell
+export CYPRESS_INSTALL_BINARY=https://cdn.cypress.io/beta/binary/3.3.2/darwin-x64/circle-develop-e5106d95f51eec477b8e66609939979fb87aab56-126014/cypress.zip
+```
+
+```shell
+npm install https://cdn.cypress.io/beta/npm/3.3.2/circle-develop-e5106d95f51eec477b8e66609939979fb87aab56-126013/cypress.tgz
+```
+
+If my machine is Windows 64bit, I will click on the "Testing new win32 x64 ..." commit and run the command below.
+
+```shell
+set CYPRESS_INSTALL_BINARY=https://cdn.cypress.io/beta/binary/3.3.2/win32-x64/appveyor-develop-e5106d95f51eec477b8e66609939979fb87aab56-25451270/cypress.zip
+```
+
+```shell
+npm install https://cdn.cypress.io/beta/npm/3.3.2/appveyor-develop-e5106d95f51eec477b8e66609939979fb87aab56-25451270/cypress.tgz
+```
+
+On Linux CI you should install the binary from the "Testing new linux x64 ..." commit.
+
+```shell
+export CYPRESS_INSTALL_BINARY=https://cdn.cypress.io/beta/binary/3.3.2/linux-x64/circle-develop-e5106d95f51eec477b8e66609939979fb87aab56-125973/cypress.zip
+```
+
+```shell
+npm install https://cdn.cypress.io/beta/npm/3.3.2/circle-develop-e5106d95f51eec477b8e66609939979fb87aab56-125992/cypress.tgz
+```
+
+### Pre-release binary URL format
+
+The above `CYPRESS_INSTALL_BINARY` urls are temporary - they are purged after 30 days. The format of the url is as follows:
+
+```text
+https://cdn.cypress.io/beta/binary/<version>/<platform>-<arch>/
+<ci name>-<branch name>-<full commit SHA>-<CI build number>/cypress.zip
+```