Creating Debian repository access from files in a local dir

Let's say `MYDIR` is a directory somewhere in my homedir.

I use the following `Makefile` in `MYDIR`.

```makefile
all:
	dpkg-scanpackages . > Packages
	gzip < Packages > Packages.gz
	apt-ftparchive -o "APT::FTPArchive::Release::Origin=local-debs" release . > Release
	gpg --clearsign -o InRelease Release
	gpg -abs -o Release.gpg Release
	gpg --export MYEMAIL >local-archive-kerying.gpg
```

I create the following `/etc/apt/sources.list.d/local.list` file:

```sources.list
deb [signed-by=/usr/share/keyrings/local-archive-keyring.gpg] file:///MYDIR ./
```

When using `apt update` it claims my PUBKEY is not available even if I put it at the right place, i.e. `/usr/share/keyrings/local-archive-keyring.gpg