gitlab not displaying gitlab-runner output in spite of builds running to completion

Question

I've looked at:

Gitlab CI runner not building or showing any output

But this isn't a case of upgrading from gitlab 7 to 8. Even so, I tried deleting the build directory and that hasn't solved my issue.

The build triggers, and some of the stages pass and other stages fail, so the runner appears to be doing its job. And I can get the raw output.

But for some reason the build page in gitlab is not displaying the build output.

Here is my .gitlab-ci.yml file:

# This file is a template, and might need editing before it works on your project.
---
# Build JAVA applications using Apache Maven (http://maven.apache.org)
# For docker image tags see https://hub.docker.com/_/maven/
#
# For general lifecycle information see https://maven.apache.org/guides/introduction/introduction-to-the-lifecycle.html
# 
# This template will build and test your projects as well as create the documentation.
# 
# * Caches downloaded dependencies and plugins between invocation.
# * Does only verify merge requests but deploy built artifacts of the
#   master branch.
# * Shows how to use multiple jobs in test stage for verifying functionality
#   with multiple JDKs.
# * Uses site:stage to collect the documentation for multi-module projects.
# * Publishes the documentation for `master` branch.

variables:
  # This will supress any download for dependencies and plugins or upload messages which would clutter the console log.
  # `showDateTime` will show the passed time in milliseconds. You need to specify `--batch-mode` to make this work.
  MAVEN_OPTS: "-Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=WARN -Dorg.slf4j.simpleLogger.showDateTime=true -Djava.awt.headless=true"
  # As of Maven 3.3.0 instead of this you may define these options in `.mvn/maven.config` so the same config is used
  # when running from the command line.
  # `installAtEnd` and `deployAtEnd`are only effective with recent version of the corresponding plugins.
  MAVEN_CLI_OPTS: "--batch-mode --errors --fail-at-end --show-version -DinstallAtEnd=true -DdeployAtEnd=true"

# Cache downloaded dependencies and plugins between builds.
cache:
  paths:
    - /root/.m2/repository/

# This will only validate and compile stuff and run e.g. maven-enforcer-plugin. 
# Because some enforcer rules might check dependency convergence and class duplications
# we use `test-compile` here instead of `validate`, so the correct classpath is picked up.
.validate: &validate
  stage: build
  script:
    - 'mvn $MAVEN_CLI_OPTS test-compile'

# For merge requests do not `deploy` but only run `verify`.
# See https://maven.apache.org/guides/introduction/introduction-to-the-lifecycle.html
.verify: &verify
  stage: test
  script:
    - 'mvn $MAVEN_CLI_OPTS verify site site:stage'
  except:
    - master

# Validate merge requests using JDK7
validate:jdk7:
  <<: *validate
  image: maven:3.3.9-jdk-7

# Validate merge requests using JDK8
validate:jdk8:
  <<: *validate
  image: maven:3.3.9-jdk-8

# Verify merge requests using JDK7
verify:jdk7:
  <<: *verify
  image: maven:3.3.9-jdk-7

# Verify merge requests using JDK8
verify:jdk8:
  <<: *verify
  image: maven:3.3.9-jdk-8


# For `master` branch run `mvn deploy` automatically.
# Here you need to decide whether you want to use JDK7 or 8.
# To get this working you need to define a volume while configuring your gitlab-ci-multi-runner.
# Mount your `settings.xml` as `/root/.m2/settings.xml` which holds your secrets.
# See https://maven.apache.org/settings.html
deploy:jdk8:
  # Use stage test here, so the pages job may later pickup the created site.
  stage: test
  script:
    - 'mvn $MAVEN_CLI_OPTS deploy site site:stage'
  only:
    - master
  # Archive up the built documentation site.
  artifacts:
    paths:
    - target/staging
  image: maven:3.3.9-jdk-8


pages:
  image: busybox:latest
  stage: deploy
  script:
    # Because Maven appends the artifactId automatically to the staging path if you did define a parent pom,
    # you might need to use `mv target/staging/YOUR_ARTIFACT_ID public` instead.
    - mv target/staging public
  dependencies:
    - deploy:jdk8
  artifacts:
    paths:
    - public
  only:
    - master