regression in 19.8.4 regarding task execution order

[mikonse]

Current Behavior

When describing task dependencies via nx.json we'd expect those task dependencies to be honored (i.e. executed one after another) when running with nx run-many and parallel set to a value greater than one in the nx.json

With nx versions 20.0.0 as well as 19.8.4 and 19.5.8 (almost certainly introduced by #28227) task dependency order is not properly followed by nx.

E.g. with an nx.json like

{
  "targetDefaults": {
    "pretest": {
      "cache": true,
      "dependsOn": ["^prebuild", "prebuild"]
    },
    "test": {
      "dependsOn": ["pretest"],
      "cache": true,
    }
  }
}

And two projects (p1 and p2), where p1 defines a prebuild task and p2 depends on p1

Running nx run-many --target pretest --parallel 10 can now result in a situation where p2:pretest and p1:prebuild are executed at the same time which might lead to errors if p1:prebuild is some sort of code-generation step upon which p2 depends.

I haven't been able to come up wth a minimal example to reproduce this but the issue was introduced in all nx releases which included #28227. That PR apparently reworked the way the project graph is built quite a bit and maybe introduced some inconsistencies

Expected Behavior

The task dependency order should be adhered to as expected. Tasks which depend upon one another MUST not be executed in parallel when running via nx run-many.

Steps to Reproduce

1. Have task dependencies between multiple projects
2. Run via nx run-many and a large enough parallel setting
3. Observe tasks which are dependent upon one another be executed at the same time.

Nx Report

Node           : 20.18.0
OS             : linux-x64
Native Target  : x86_64-linux
npm            : 10.8.2

nx                 : 20.0.0
@nx/js             : 20.0.0
@nx/jest           : 20.0.0
@nx/eslint         : 20.0.0
@nx/workspace      : 20.0.0
@nrwl/workspace    : 17.3.2
@nx/devkit         : 20.0.0
@nx/eslint-plugin  : 20.0.0
@nx/node           : 20.0.0
@nx/plugin         : 20.0.0
@nx/react          : 20.0.0
@nx/rollup         : 20.0.0
@nrwl/tao          : 17.3.2
@nx/web            : 20.0.0
@nx/webpack        : 20.0.0
typescript         : 5.6.2
---------------------------------------
Registered Plugins:
@nx/jest/plugin
@rs-box-apps/workspace-plugin
@nx/eslint/plugin
---------------------------------------
Community plugins:
@jscutlery/semver   : 5.3.1
@rs-temaf/nx.gitlab : 0.5.0
@rs-temaf/nx.rs-run : 0.2.0
@rscocdip/nx        : 1.1.1
---------------------------------------
Local workspace plugins:
         @rs-box-apps/workspace-plugin
---------------------------------------
The following packages should match the installed version of nx
  - @nrwl/workspace@17.3.2
  - @nrwl/tao@17.3.2

Operating System

• macOS
• Linux
• Windows
• Other (Please specify)

[hschmidtchen]

We are facing the same issue attempting to upgrade form 19.5.7 to 19.8.4.

Running a set of validations with yarn nx run-many --all --target=validate --parallel=1 causes a crucial build dependency task to be executed as the very last step instead of before the validation targets.

If I execute the validation targets one by one without run-many, execution does not fail.

Nx Report

Node           : 20.16.0
OS             : linux-x64
Native Target  : x86_64-linux
yarn           : 4.4.0

nx                 : 19.8.4
@nx/js             : 19.8.4
@nx/jest           : 19.8.4
@nx/linter         : 19.8.4
@nx/eslint         : 19.8.4
@nx/workspace      : 19.8.4
@nx/angular        : 19.8.4
@nx/cypress        : 19.8.4
@nx/devkit         : 19.8.4
@nx/eslint-plugin  : 19.8.4
@nx/express        : 19.8.4
@nx/nest           : 19.8.4
@nx/node           : 19.8.4
@nrwl/tao          : 19.8.4
@nx/web            : 19.8.4
@nx/webpack        : 19.8.4
typescript         : 5.4.5
---------------------------------------
Registered Plugins:
@nxlv/python
---------------------------------------
Community plugins:
@ionic/angular         : 8.3.2
@ionic/angular-toolkit : 11.0.1
@luzmo/ngx-embed       : 6.3.4
@ngneat/spectator      : 18.0.2
@ngrx/component        : 17.2.0
@ngrx/component-store  : 17.2.0
@ngrx/effects          : 17.2.0
@ngrx/entity           : 17.2.0
@ngrx/router-store     : 17.2.0
@ngrx/store            : 17.2.0
@ngrx/store-devtools   : 17.2.0
@nxlv/python           : 19.1.3
ngx-toastr             : 19.0.0
ngx-ui-loader          : 13.0.0

[xiongemi]

i suspect it might be related to this github issue #26929

[xiongemi]

also might to relate to github issue #28599

[xiongemi]

fixed in pr #28669