found it like this

Dockerfile

@@ -46,6 +46,8 @@ ARG SYSTEM_PACKAGES="\
     tmux \
 "
 
+RUN /bin/bash -c "echo -e 'Y\n\n' | /usr/local/sbin/unminimize"
+
 RUN \
     apt update && \
     apt -y upgrade && \

Makefile

@@ -10,4 +10,4 @@ build:
 		2>&1 | tee -a build.log
 
 enter:
-	docker run -ti --rm=true -e HOME=/home/user -e USER=user --user=user -v /home/sneak:/home/user/.home sneak/work /home/user/.nix-profile/bin/zsh
+	docker run -ti --rm=true -e HOME=/home/user -e USER=user --user=user -v /home/sneak:/home/user/.home sneak/work /home/user/.nix-profile/bin/zsh -l

build/root.sh

@@ -44,7 +44,7 @@ ln -s /hostroot/root /root/.home
 
 mkdir -p /home/user/.ssh
 cp /root/.ssh/authorized_keys /home/user/.ssh/authorized_keys
-echo chown -Rv $UID_TO_ADD:$GID_TO_ADD /home/user
-chown -Rv $UID_TO_ADD:$GID_TO_ADD /home/user
-
+chown -R $UID_TO_ADD:$GID_TO_ADD /home/user
 echo "$USERNAME_TO_ADD ALL=(ALL) NOPASSWD: ALL" > /etc/sudoers.d/user
+
+

build/user.sh

@@ -34,6 +34,7 @@ nix-env -i myPackages
 # oh-my-zsh
 curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh > /tmp/installomz.sh
 export ZSH="$HOME/.zsh"
+export KEEP_ZSHRC=yes
 zsh /tmp/installomz.sh && rm /tmp/installomz.sh
 
 

root/etc/service/sshd/run

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+exec /usr/sbin/sshd -D

root/home/user/.config/nixpkgs/config.nix

@@ -25,6 +25,7 @@
         vim
         weechat
         wget
+        zsh
       ];
     };