#19860 Support nested `.gitignore` files in `--pants-ignore-use-gitignore` Issue created by stuhood After #5682 and #18649, the situation is that Pants uses the root and global

.gitignore

files when

--pants-ignore-use-gitignore

is enabled (as it is by default). This ticket covers supporting non-root/global

.gitignore

files in child directories. * * * The implementation of

--pants-ignore-use-gitignore

initially used a naive recursive-upward parse of

.gitignore

files: this meant that for every file-ignore lookup, we would re-parse all parent

.gitignore

files. Consequently, that aspect was skipped in #9310. Instead, in order to support nested

.gitignore

files efficiently while watching changes made to them, we would need to add recursive-upward memoization of

.gitignore

parsing. The memoization could either be accomplished by: 1. creating a new

Gitignore

node, which recursively depended upwards on itself to parse parent

Gitignore

nodes. 2. adding

Gitignore

information to the `Scandir` node, such that whenever we called

Scandir

on a directory, we also exposed and memoized a GitignoreStyleExcludes struct from the

Node

. Then,

Scandir

nodes would recursively depend on the parent

Scandir

node. To reduce overhead (by creating fewer

Nodes

), I think that approach 2 would be cleaner. But if it ended up increasing complexity too much, then approach 1 would be fine as well. pantsbuild/pants