我在Wercker中使用了我的项目构建docker image，我这样做是因为我认为在环境中安装了需要的软件包比在项目的每个版本中安装它们要好。
然而，现在Wercker每次都必须构建我的项目失败，原因是什么？超时，因为设置环境步骤需要超过5分钟。
Running wercker version: 1.0.405 (Compiled at: 2016-02-10T22:17:21Z, Git commit: b44ceb57f107c85dbaa619c6d89592b979f69b5b)
Using config:
box: shackra/latex-ebook
build:
steps:
- script:
name: Documento en formato PDF
code: |
xelatex --version
# twice, please
xelatex biblia.tex
xelatex biblia.tex
- script:
name: Subir documentos a Bitbucket
code: |
./upload-to-bitbucket.sh $BITBUCKET_U $BITBUCKET_P /straubingerdigital/biblia-platense/downloads biblia.pdf
Pulling from shackra/latex-ebook: latest
Pulling fs layer: e627a276e4dc
Pulling fs layer: 16c1e3a61000
Pulling fs layer: 80bc33a4179a
Pulling fs layer: d23822bfcf6d
Pulling fs layer: 4fdf7f1f2966
Pulling fs layer: f6a9cd9eb099
Pulling fs layer: 85a462562b69
Pulling fs layer: 73a2d7fa1951
Pulling fs layer: 56fffce111ea
Verifying Checksum: 16c1e3a61000
Download complete: 16c1e3a61000
Verifying Checksum: 56fffce111ea
Download complete: 56fffce111ea
Verifying Checksum: 80bc33a4179a
Download complete: 80bc33a4179a
Verifying Checksum: d23822bfcf6d
Download complete: d23822bfcf6d
Verifying Checksum: 4fdf7f1f2966
Download complete: 4fdf7f1f2966
Verifying Checksum: 85a462562b69
Download complete: 85a462562b69
Verifying Checksum: 73a2d7fa1951
Download complete: 73a2d7fa1951
Verifying Checksum: e627a276e4dc
Download complete: e627a276e4dc
Pull complete: e627a276e4dc
Pull complete: 16c1e3a61000
Pull complete: 80bc33a4179a
Pull complete: d23822bfcf6d
Pull complete: 4fdf7f1f2966
Verifying Checksum: f6a9cd9eb099
Download complete: f6a9cd9eb099
Pull complete: f6a9cd9eb099
Pull complete: 85a462562b69
Pull complete: 73a2d7fa1951
Pull complete: 56fffce111ea
Digest: sha256:af688a72e89b3a97b5b4d28509291a30be7a6d4b0067180f46f5d97da22679c8
Status: Downloaded newer image for shackra/latex-ebook:latest
它只是停留在Status: Downloaded newer image for shackra/latex-ebook:latest，这里出了什么问题？我可以从我的Wercker配置文件中修复一下吗？