Cannot create empty file (for mutable)

[woky]

In order to write a file, it has to be listed in contents as mutable. However, if the file doesn't exist in package archive, it has to be created with non-empty text, otherwise chisel fails with no content error.

Demonstration:

$ cat slices/ca-certificates.yaml
package: ca-certificates
slices:
  data:
    contents:
      /etc/ssl/certs/ca-certificates.crt: { text: "", mutable: true }
    mutate: |
      content.write("/etc/ssl/certs/ca-certificates.crt", "foobar")
$ chisel cut --release $PWD --root ~/tmp/chisel-out ca-certificates_data
...
2022/06/10 09:07:38 Extracting files from package "ca-certificates"...
error: cannot extract from package "ca-certificates": no content at /etc/ssl/certs/ca-certificates.crt

It works when I explicitly set file text to non-empty value, e.g.:

$ cat slices/ca-certificates.yaml
package: ca-certificates
slices:
  data:
    contents:
      /etc/ssl/certs/ca-certificates.crt: { text: "todo", mutable: true }
    mutate: |
      content.write("/etc/ssl/certs/ca-certificates.crt", "foobar")