title: GitLab CI/CD cache error: The filename, directory name, or volume label syntax is incorrect
body: <p>I am having GitLab-Runner installed and running on Windows Server 2012. I am trying to cache <code>node_modules</code> folder.<br>
  I followed many examples found on internet and write this yml:</p>
  
  <pre><code>cache:
    key: "%CI_PROJECT_NAME%"       #Defines when to cache.
    untracked: true
    paths:
      - node_modules/
  
  variables:
      SOLUTION: $CI_PROJECT_DIR\App.Web.sln
  
  stages:
      - setup
      - build
  
  setup:                                                                                      #From: https://gitlab.com/gitlab-org/gitlab-ce/issues/12963
      stage: setup
      script:
          - npm install                                                                       #Install all packages
  
  build_backend:
      stage: build
      script:
          - echo "Building backend branch '%CI_COMMIT_REF_NAME%' for '%SOLUTION%'."
          - dotnet restore "%SOLUTION%"
          - dotnet msbuild /p:Configuration=Release "%SOLUTION%"
      except:
          - tags
  
  build_frontend:
      stage: build
      script:
          - echo "Building frontend branch '%CI_COMMIT_REF_NAME%' for '%SOLUTION%'."
          - npm run build:vendor &amp;&amp; npm run build:webpack
      except:
          - tags
  </code></pre>
  
  <p>My <code>setup</code> stage run successfully(job is moved to build stage), but there are fatal errors and caching is never performed.<br>
  If we look in detail why it failed, path really is strange:</p>
  
  <pre><code>FATAL: open ..\..\..\..\..\cache\web\app\app:1\cache.zip: The filename, directory name, or volume label syntax is incorrect.
                              |     |   |    |
                             (1)   (2) (3)  (4)
                                            ??? 
  (1) This is GitLab-Runner root dir
  (2) GitLab group for project
  (3) Project name
  (4) I think this cause problems, because aap:1 is invalid dir name.
  </code></pre>
  
  <p>Full Log:</p>
  
  <pre><code>Running with gitlab-runner 10.4.0 (857480b6)
    on Dexter (7cab42e4)
  Using Shell executor...
  Running on DEXTER...
  Fetching changes...
  HEAD is now at b0344f2 Fix
  Checking out 692e0373 as 51-move-ci-cd-to-docker...
  Skipping Git submodules setup
  Checking cache for %CI_PROJECT_NAME%:1...
  FATAL: open ..\..\..\..\..\cache\web\app\app:1\cache.zip: The filename, directory name, or volume label syntax is incorrect. 
  Successfully extracted cache
  $ npm install
  ....
  ....
  added 1489 packages in 245.681s
  Creating cache %CI_PROJECT_NAME%:1...
  node_modules/: found 47345 matching files          
  WARNING: GetFileAttributesEx ..\..\..\..\..\cache\web\app\app:1\cache.zip: The filename, directory name, or volume label syntax is incorrect. 
  FATAL: open ..\..\..\..\..\cache\web\app\:1\archive_428238003: The filename, directory name, or volume label syntax is incorrect. 
  Created cache
  Job succeeded
  </code></pre>
  
  <p>I also try without <code>cache:key</code> but error is more or less the same:</p>
  
  <pre><code>FATAL: open ..\..\..\..\..\cache\web\app\default:1\cache.zip: The filename, directory name, or volume label syntax is incorrect. 
  </code></pre>