Repository navigation
Docs falsely state that lazy-trees are enabled by default #328
Description
Docs:
Lazy trees are currently stable in Determinate Nix and enabled by default for all users.
But lazy-trees is disabled by default in the current version (3.15.2).
Also, github:DeterminateSystems/determinate#nixosModules.default doesn't enable lazy-trees in nix.conf.
To check that lazy-trees is off by default, ensure that nix.conf doesn't enable it and then run:
# Create tmp flake
mkdir -p /tmp/tmpflake
echo '{ outputs = _: { lib.a = "a"; }; }' > /tmp/tmpflake/flake.nix
touch /tmp/tmpflake/mydummyfile.tmp
(cd /tmp/tmpflake && git init && git add . && git commit -m init)
nix eval /tmp/tmpflake#lib.a
# Check that flake src was copied
ls /nix/store/*/mydummyfile.tmp
Activity
grahamc commentedon Jan 28, 2026
This default probably should be improved in nix-src itself, but this is true for users of Determinate Nix which specifically includes running the
determinate-nixddaemon. The daemon always writes out anix.confwhich enables lazy-trees.erikarvstedt commentedon Jan 28, 2026
My user story was:
Because
lazy-treesis a client feature, not a daemon feature, I assumed the default was implemented in the client. Which, I think, is a reasonable assumption.grahamc commentedon Jan 28, 2026
Makes sense, thanks! I'll file a ticket internally too