Run builds in series

Since they I/O bound off of the same hardware, and sometimes also CPU
bound when compiling things, running them in parallel only slows
things down.

Closes: #28

pipelines/jobs/rust-xwin.yml.j2

@@ -16,36 +16,36 @@
 
 {% macro jobs() -%}
   - name: rust-xwin
+    serial: true
     plan:
       - get: repo
         trigger: true
-      - in_parallel:
-          fail_fast: true
-          steps:
-            - task: build-rust-xwin
-              file: repo/tasks/build-image.yml
-              privileged: true
-              vars:
-                context: repo/images/rust-xwin
-                target: rust-xwin
-                dockerfile: ''
-              output_mapping:
-                image: image-rust-xwin
-            - task: build-rust-xwin-ci
-              file: repo/tasks/build-image.yml
-              privileged: true
-              vars:
-                context: repo/images/rust-xwin
-                target: rust-xwin-ci
-                dockerfile: ''
-              output_mapping:
-                image: image-rust-xwin-ci
+      - task: build-rust-xwin
+        file: repo/tasks/build-image.yml
+        privileged: true
+        vars:
+          context: repo/images/rust-xwin
+          target: rust-xwin
+          dockerfile: ''
+        output_mapping:
+          image: image-rust-xwin
+      - task: build-rust-xwin-ci
+        file: repo/tasks/build-image.yml
+        privileged: true
+        vars:
+          context: repo/images/rust-xwin
+          target: rust-xwin-ci
+          dockerfile: ''
+        output_mapping:
+          image: image-rust-xwin-ci
       - in_parallel:
           steps:
             - put: image-rust-xwin
-              params:
-                image: image-rust-xwin/image.tar
+              inputs: detect
+              params: { image: image-rust-xwin/image.tar }
+              no_get: true
             - put: image-rust-xwin-ci
-              params:
-                image: image-rust-xwin-ci/image.tar
+              inputs: detect
+              params: { image: image-rust-xwin-ci/image.tar }
+              no_get: true
 {% endmacro %}

pipelines/jobs/simple-image.yml.j2

@@ -1,5 +1,6 @@
 {% macro jobs(job) -%}
   - name: {{ job.name }}
+    serial: true
     plan:
       - get: repo
         trigger: true
@@ -17,5 +18,7 @@
         {%- endfor %}
         {%- endif %}
       - put: image-{{ job.name }}
+        inputs: detect
         params: { image: image/image.tar }
+        no_get: true
 {%- endmacro -%}