nix-super/src/libexpr/flake/call-flake.nix
Eelco Dolstra 071dd2b3a4 Input: Replace 'locked' bool by isLocked() method
It's better to just check whether the input has all the attributes
needed to consider itself locked (e.g. whether a Git input has an
'rev' attribute).

Also, the 'locked' field was actually incorrect for Git inputs: it
would be set to true even for dirty worktrees. As a result, we got
away with using fetchTree() internally even though fetchTree()
requires a locked input in pure mode. In particular, this allowed
'--override-input' to work by accident.

The fix is to pass a set of "overrides" to call-flake.nix for all the
unlocked inputs (i.e. the top-level flake and any --override-inputs).
2024-02-20 16:59:15 +01:00

85 lines
2.6 KiB
Nix

# This is a helper to callFlake() to lazily fetch flake inputs.
# The contents of the lock file, in JSON format.
lockFileStr:
# A mapping of lock file node IDs to { sourceInfo, subdir } attrsets,
# with sourceInfo.outPath providing an InputAccessor to a previously
# fetched tree. This is necessary for possibly unlocked inputs, in
# particular the root input, but also --override-inputs pointing to
# unlocked trees.
overrides:
let
lockFile = builtins.fromJSON lockFileStr;
# Resolve a input spec into a node name. An input spec is
# either a node name, or a 'follows' path from the root
# node.
resolveInput = inputSpec:
if builtins.isList inputSpec
then getInputByPath lockFile.root inputSpec
else inputSpec;
# Follow an input path (e.g. ["dwarffs" "nixpkgs"]) from the
# root node, returning the final node.
getInputByPath = nodeName: path:
if path == []
then nodeName
else
getInputByPath
# Since this could be a 'follows' input, call resolveInput.
(resolveInput lockFile.nodes.${nodeName}.inputs.${builtins.head path})
(builtins.tail path);
allNodes =
builtins.mapAttrs
(key: node:
let
sourceInfo =
if overrides ? ${key}
then
overrides.${key}.sourceInfo
else
# FIXME: remove obsolete node.info.
fetchTree (node.info or {} // removeAttrs node.locked ["dir"]);
subdir = overrides.${key}.dir or node.locked.dir or "";
outPath = sourceInfo + ((if subdir == "" then "" else "/") + subdir);
flake = import (outPath + "/flake.nix");
inputs = builtins.mapAttrs
(inputName: inputSpec: allNodes.${resolveInput inputSpec})
(node.inputs or {});
outputs = flake.outputs (inputs // { self = result; });
result =
outputs
# We add the sourceInfo attribute for its metadata, as they are
# relevant metadata for the flake. However, the outPath of the
# sourceInfo does not necessarily match the outPath of the flake,
# as the flake may be in a subdirectory of a source.
# This is shadowed in the next //
// sourceInfo
// {
# This shadows the sourceInfo.outPath
inherit outPath;
inherit inputs; inherit outputs; inherit sourceInfo; _type = "flake";
};
in
if node.flake or true then
assert builtins.isFunction flake.outputs;
result
else
sourceInfo
)
lockFile.nodes;
in allNodes.${lockFile.root}