kustomize: KRM Exec Function can't locate executable when referencing a base

Describe the bug

When using a KRM exec function with a relative path to the kustomization.yaml file, the executable can’t be found when referencing a base from a variant.

It appears the function is “exec”-d relative to the base not the variant.

Things are further complicated when the base references another remote base.

Files that can reproduce the issue

# dir
.
├── base
│   ├── deployment.yaml
│   └── kustomization.yaml
└── krm-exec
    ├── krm-config.yaml
    ├── kustomization.yaml
    └── plugins
        └── function.sh

# base/kustomization.yaml

resources:
 - deployment.yaml

# base/deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: app1
spec:
  selector:
    matchLabels:
      app: hello
  template:
    metadata:
      labels:
        app: hello
    spec:
      containers:
      - name: busybox
        image: busybox:v1.0.0

#krm-exec/kustomization.yaml
resources:
- ../base
transformers:
- krm-config.yaml

#krm-exec/krm-config.yaml
apiVersion: my.example.io/v1
kind: MyPlugin
metadata:
  name: notImportantHere
  annotations:
    config.kubernetes.io/function: |
      exec: 
        path: ./plugins/function.sh

#krm-exec/plugins/function.sh
#!/bin/bash
resourceList=$(cat) 
# dummy
echo "$resourceList"

Expected output

The dummy function should just echo out the resources read from stdin.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: app1
spec:
  selector:
    matchLabels:
      app: hello
  template:
    metadata:
      labels:
        any: thing
    spec:
      containers:
      - name: busybox
        image: busybox:v1.0.0
     

Actual output

#from krm-exec dir
kustomize build --enable-alpha-plugins --enable-exec  .
Error: couldn't execute function: fork/exec ./plugins/function.sh: no such file or directory

Kustomize version

kustomize version
{Version:kustomize/v4.4.1 GitCommit:b2d65ddc98e09187a8e38adc27c30bab078c1dbf BuildDate:2021-11-11T23:36:27Z GoOs:darwin GoArch:amd64}

Platform

macOS ( M1 ) darwin21.0 arm64

Additional context

Some other scenarios:

• The plugin works as expected when the variant kustomization does not reference the base, but a relative deployment.

#krm-exec/kustomizaiton.yaml
resources:
- deployment.yaml

• With the original setup If I move the ./plugins/function.sh to the base, the plugin works even if the krm-function.yaml is located in the variant

To further complicate things, if I add a remote base to the local base I get this error:

#base/kustomization.yaml
resources:
 - https://github.com/pmcjury/somerepo/manifests/base?ref=main
 - deployment.yaml

#from krm-exec dir
kustomize build --enable-alpha-plugins --enable-exec  .
Error: couldn't execute function: chdir /private/var/folders/yn/88ww9kqx1b35xylvc0wt0fb80000gn/T/kustomize-124974724/deploy/manifests/base: no such file or directory