Ghost cli installation sources

Hi everyone, i got a quesiton.
I have a local ghost repo and making changes in it - for example i attached as a submodule other theme.
I fixed docker issue and now container builds ok - i found another docker build file.
However this file builds ghost via ghost-cli.
So my question about that applet. When it running like

gosu node ghost install "$GHOST_VERSION" --db sqlite3 --no-prompt --no-stack --no-setup --dir "$GHOST_INSTALL";

Which sources it using? from my repo i mean local something else.
I ask because new theme won’t be transferred to content folder this way. So it deploys ghost without any customization.

Please help