• Numerous test tasks compile their binaries instead of using artefacts from the previous compile task.
• At least some of these compilations done without using MongoDB toolchain; the build happens to use system provided compiler and other tools.
• The Evergreen expansions for compile task are ignored.

Examples:
unit-test task relies on build artefacts from previous compile task:

  - name: unit-test
    tags: ["python"]
    depends_on: 
    - name: compile
    commands: 
      - func: "fetch artifacts"
      - func: "unit test"

format-test task re-builds the project without properly invoking compile task:

  - name: format-test
    tags: ["pull_request"]
    commands: 
      - func: "get project"
      - func: "compile wiredtiger"
      - func: "make check directory"
        vars: 
          directory: test/format

TODO:

• Fix all test tasks to use pre-built artefacts from compile task, instead of building their own
• Add dependency on compile task to all relevant test tasks where such dependency is missing