Write to log file when using DEBUG=* (#17906)

RobinMalfait · web-flow · commit d8c4df8001b8 · 2025-05-07T10:19:54.000-04:00
This PR improves the debugability of the scanner when using `DEBUG=*` by writing to a `tailwindcss-{pid}.log` file in the current working directory. It will include all the tracing information from the scanner. This PR also introduces `Discovering {path}` and `Reading {path}` logs. - `Discovering {path}` — this is logged when we are traversing the file system looking for files. We use the `ignore` crate, and log this information in the `filter_entry` callback. If a file was already ignored by `.gitignore` files, this won't show up, but it also means that we will not read it. - `Reading {path}` — this is when we are actually reading the file so we can start extracting potential Tailwind CSS classes. These will give you some insights in what paths are being scanned, and if we get stuck, where we get stuck. Also, we are appending to the file. In the log below, you can already see that a `tailwindcss-<number>.log` file exists already even though it didn't exist before running the command. This should make it easier to debug if we get stuck on a specific file/folder because the file will be populated with information. There are a few reasons for appending to a file: 1. There is a lot of output, so spamming the stdout/stderr is not ideal 2. If you run the same command again, after changing your `@source` directives, you could diff the outputs. (although, the timestamps will be different) 3. When using `DEBUG=*`, a lot of other tools also output debug information, so writing to a file should make this better. <details> <summary>Example log</summary> ```log 2025-05-06T23:13:45.912292Z INFO scan_sources: tailwindcss_oxide::scanner: enter 2025-05-06T23:13:45.912697Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/out.css" 2025-05-06T23:13:45.912716Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/tailwindcss-61347.log" 2025-05-06T23:13:45.912748Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app" 2025-05-06T23:13:45.912786Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/test" 2025-05-06T23:13:45.912814Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/test/utils.ts" 2025-05-06T23:13:45.912851Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/utils" 2025-05-06T23:13:45.912873Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/utils/flatten.ts" 2025-05-06T23:13:45.912884Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/utils/matrix.ts" 2025-05-06T23:13:45.912893Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/utils/default-map.ts" 2025-05-06T23:13:45.912904Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/tailwind.css" 2025-05-06T23:13:45.912914Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/root.tsx" 2025-05-06T23:13:45.912936Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain" 2025-05-06T23:13:45.912962Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/expression.ts" 2025-05-06T23:13:45.912972Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/walk-ast.ts" 2025-05-06T23:13:45.912995Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/signature" 2025-05-06T23:13:45.913019Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/signature/parser.test.ts" 2025-05-06T23:13:45.913029Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/signature/validate.test.ts" 2025-05-06T23:13:45.913039Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/signature/tokenizer.ts" 2025-05-06T23:13:45.913048Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/signature/validate.ts" 2025-05-06T23:13:45.913058Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/signature/parser.ts" 2025-05-06T23:13:45.913067Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/signature/tokenizer.test.ts" 2025-05-06T23:13:45.913077Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/ast.ts" 2025-05-06T23:13:45.913086Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/version-control.ts" 2025-05-06T23:13:45.913095Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/tokenizer.ts" 2025-05-06T23:13:45.913105Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/type-checker.test.ts" 2025-05-06T23:13:45.913121Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/evaluation-result.ts" 2025-05-06T23:13:45.913505Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/tmp.test.ts" 2025-05-06T23:13:45.913514Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/version-control.test.ts" 2025-05-06T23:13:45.913523Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/tokenizer.test.ts" 2025-05-06T23:13:45.913531Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/evaluation.ts" 2025-05-06T23:13:45.913554Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions" 2025-05-06T23:13:45.913583Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/sequence.test.ts" 2025-05-06T23:13:45.913592Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/date.ts" 2025-05-06T23:13:45.913601Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/lookup.test.ts" 2025-05-06T23:13:45.913613Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/statistics.ts" 2025-05-06T23:13:45.913622Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/intrinsics.test.ts" 2025-05-06T23:13:45.913631Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/math.ts" 2025-05-06T23:13:45.913640Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/engineering.ts" 2025-05-06T23:13:45.913648Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/types.test.ts" 2025-05-06T23:13:45.913656Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/text.ts" 2025-05-06T23:13:45.913665Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/text.test.ts" 2025-05-06T23:13:45.913673Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/intrinsics.ts" 2025-05-06T23:13:45.913681Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/logic.ts" 2025-05-06T23:13:45.913689Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/date.test.ts" 2025-05-06T23:13:45.913697Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/types.ts" 2025-05-06T23:13:45.913705Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/logic.test.ts" 2025-05-06T23:13:45.913713Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/lookup.ts" 2025-05-06T23:13:45.913720Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/sequence.ts" 2025-05-06T23:13:45.913728Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/engineering.test.ts" 2025-05-06T23:13:45.913741Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/index.ts" 2025-05-06T23:13:45.913749Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/math.test.ts" 2025-05-06T23:13:45.913757Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/statistics.test.ts" 2025-05-06T23:13:45.913783Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/__snapshots__" 2025-05-06T23:13:45.913817Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/spreadsheet.test.ts" 2025-05-06T23:13:45.913826Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/type-checker.ts" 2025-05-06T23:13:45.913833Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/function-utils.ts" 2025-05-06T23:13:45.913841Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/spreadsheet.ts" 2025-05-06T23:13:45.913849Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/expression.test.ts" 2025-05-06T23:13:45.913857Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/evaluation.test.ts" 2025-05-06T23:13:45.913879Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/routes" 2025-05-06T23:13:45.913896Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/app/routes/_index.tsx" 2025-05-06T23:13:45.914172Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/README.md" 2025-05-06T23:13:45.914197Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/public" 2025-05-06T23:13:45.914228Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/public/fonts" 2025-05-06T23:13:45.914268Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/package.json" 2025-05-06T23:13:45.914289Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/scripts" 2025-05-06T23:13:45.914310Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/scripts/generate-documentation.ts" 2025-05-06T23:13:45.914332Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/.github" 2025-05-06T23:13:45.914383Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/.github/workflows" 2025-05-06T23:13:45.914410Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/.github/workflows/ci.yml" 2025-05-06T23:13:45.914420Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/tsconfig.json" 2025-05-06T23:13:45.914455Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/vite.config.ts" 2025-05-06T23:13:45.914486Z INFO scan_sources: tailwindcss_oxide::scanner: Discovering "/Users/robin/github.com/RobinMalfait/spreadsheet/biome.json" 2025-05-06T23:13:45.914512Z INFO scan_sources: tailwindcss_oxide::scanner: exit 2025-05-06T23:13:45.914515Z INFO extract_candidates: tailwindcss_oxide::scanner: enter 2025-05-06T23:13:45.914518Z INFO extract_candidates:read_all_files: tailwindcss_oxide::scanner: enter 2025-05-06T23:13:45.914524Z INFO extract_candidates:read_all_files: tailwindcss_oxide::scanner: Reading 58 file(s) 2025-05-06T23:13:45.914808Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/tailwindcss-61347.log" 2025-05-06T23:13:45.914990Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/routes/_index.tsx" 2025-05-06T23:13:45.915138Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/.github/workflows/ci.yml" 2025-05-06T23:13:45.915140Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/statistics.test.ts" 2025-05-06T23:13:45.915145Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/signature/tokenizer.ts" 2025-05-06T23:13:45.915163Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/tsconfig.json" 2025-05-06T23:13:45.915153Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/engineering.ts" 2025-05-06T23:13:45.915226Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/utils/matrix.ts" 2025-05-06T23:13:45.915229Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/walk-ast.ts" 2025-05-06T23:13:45.915372Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/test/utils.ts" 2025-05-06T23:13:45.915578Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/ast.ts" 2025-05-06T23:13:45.915599Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/signature/validate.ts" 2025-05-06T23:13:45.915637Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/version-control.ts" 2025-05-06T23:13:45.915647Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/signature/parser.ts" 2025-05-06T23:13:45.915657Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/vite.config.ts" 2025-05-06T23:13:45.915680Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/types.test.ts" 2025-05-06T23:13:45.915681Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/utils/flatten.ts" 2025-05-06T23:13:45.915701Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/signature/parser.test.ts" 2025-05-06T23:13:45.915706Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/README.md" 2025-05-06T23:13:45.915691Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/utils/default-map.ts" 2025-05-06T23:13:45.915701Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/spreadsheet.test.ts" 2025-05-06T23:13:45.915730Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/package.json" 2025-05-06T23:13:45.915753Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/tokenizer.ts" 2025-05-06T23:13:45.915731Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/biome.json" 2025-05-06T23:13:45.915787Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/signature/validate.test.ts" 2025-05-06T23:13:45.915822Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/signature/tokenizer.test.ts" 2025-05-06T23:13:45.915826Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/text.ts" 2025-05-06T23:13:45.915885Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/root.tsx" 2025-05-06T23:13:45.915885Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/types.ts" 2025-05-06T23:13:45.915886Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/type-checker.ts" 2025-05-06T23:13:45.915990Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/type-checker.test.ts" 2025-05-06T23:13:45.915995Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/text.test.ts" 2025-05-06T23:13:45.915998Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/logic.ts" 2025-05-06T23:13:45.916000Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/intrinsics.ts" 2025-05-06T23:13:45.916024Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/sequence.ts" 2025-05-06T23:13:45.916056Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/function-utils.ts" 2025-05-06T23:13:45.916058Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/scripts/generate-documentation.ts" 2025-05-06T23:13:45.916070Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/expression.ts" 2025-05-06T23:13:45.916075Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/logic.test.ts" 2025-05-06T23:13:45.916063Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/date.test.ts" 2025-05-06T23:13:45.916119Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/evaluation-result.ts" 2025-05-06T23:13:45.916120Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/index.ts" 2025-05-06T23:13:45.916148Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/expression.test.ts" 2025-05-06T23:13:45.916152Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/engineering.test.ts" 2025-05-06T23:13:45.916193Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/lookup.ts" 2025-05-06T23:13:45.916219Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/tmp.test.ts" 2025-05-06T23:13:45.916228Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/tokenizer.test.ts" 2025-05-06T23:13:45.916245Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/evaluation.test.ts" 2025-05-06T23:13:45.916256Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/spreadsheet.ts" 2025-05-06T23:13:45.916253Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/lookup.test.ts" 2025-05-06T23:13:45.916267Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/sequence.test.ts" 2025-05-06T23:13:45.916287Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/math.test.ts" 2025-05-06T23:13:45.916286Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/version-control.test.ts" 2025-05-06T23:13:45.916317Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/intrinsics.test.ts" 2025-05-06T23:13:45.916323Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/evaluation.ts" 2025-05-06T23:13:45.916354Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/statistics.ts" 2025-05-06T23:13:45.916562Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/date.ts" 2025-05-06T23:13:45.916609Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/domain/functions/math.ts" 2025-05-06T23:13:45.916676Z INFO extract_candidates:read_all_files: tailwindcss_oxide::scanner: exit 2025-05-06T23:13:45.916682Z INFO extract_candidates:parse_all_blobs: tailwindcss_oxide::scanner: enter 2025-05-06T23:13:45.916688Z INFO extract_candidates:parse_all_blobs:extract: tailwindcss_oxide::scanner: enter 2025-05-06T23:13:45.918271Z INFO extract_candidates:parse_all_blobs:extract: tailwindcss_oxide::scanner: exit 2025-05-06T23:13:45.918282Z INFO extract_candidates:parse_all_blobs: tailwindcss_oxide::scanner: exit 2025-05-06T23:13:45.918286Z INFO extract_candidates:read_all_files: tailwindcss_oxide::scanner: enter 2025-05-06T23:13:45.918288Z INFO extract_candidates:read_all_files: tailwindcss_oxide::scanner: Reading 2 file(s) 2025-05-06T23:13:45.918315Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/app/tailwind.css" 2025-05-06T23:13:45.918504Z INFO tailwindcss_oxide::scanner: Reading "/Users/robin/github.com/RobinMalfait/spreadsheet/out.css" 2025-05-06T23:13:45.918512Z INFO extract_candidates:read_all_files: tailwindcss_oxide::scanner: exit 2025-05-06T23:13:45.918519Z INFO extract_candidates:extract_css_variables: tailwindcss_oxide::scanner: enter 2025-05-06T23:13:45.918522Z INFO extract_candidates:extract_css_variables:extract: tailwindcss_oxide::scanner: enter 2025-05-06T23:13:45.918635Z INFO extract_candidates:extract_css_variables:extract: tailwindcss_oxide::scanner: exit 2025-05-06T23:13:45.918640Z INFO extract_candidates:extract_css_variables: tailwindcss_oxide::scanner: exit 2025-05-06T23:13:45.919059Z INFO extract_candidates: tailwindcss_oxide::scanner: exit ``` </details> We also output where we are writing the file to. This looks like this when using the CLI: <img width="1462" alt="image" src="https://github.com/user-attachments/assets/79c2cc95-adea-4bbd-a4f1-101de45726f5" /> Last but not least, this also ignores `.log` files by default ## Test plan Ran the CLI (but you can use any tool real, since this is implemented in Oxide) with the `DEBUG=*` flag. The file generated, looks like the example I shared above.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -10,14 +10,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - Upgrade: Automatically convert candidates with arbitrary values to their utilities ([#17831](https://github.com/tailwindlabs/tailwindcss/pull/17831), [#17854](https://github.com/tailwindlabs/tailwindcss/pull/17854))
+- Write to log file when using `DEBUG=*` ([#17906](https://github.com/tailwindlabs/tailwindcss/pull/17906))
 
 ### Fixed
 
 - Ensure negative arbitrary `scale` values generate negative values ([#17831](https://github.com/tailwindlabs/tailwindcss/pull/17831))
 - Fix HAML extraction with embedded Ruby ([#17846](https://github.com/tailwindlabs/tailwindcss/pull/17846))
 - Don't scan files for utilities when using `@reference` ([#17836](https://github.com/tailwindlabs/tailwindcss/pull/17836))
 - Fix incorrectly replacing `_` with ` ` in arbitrary modifier shorthand `bg-red-500/(--my_opacity)` ([#17889](https://github.com/tailwindlabs/tailwindcss/pull/17889))
-- Upgrade: Bump dependendencies in parallel and make the upgrade faster ([#17898](https://github.com/tailwindlabs/tailwindcss/pull/17898))
+- Upgrade: Bump dependencies in parallel and make the upgrade faster ([#17898](https://github.com/tailwindlabs/tailwindcss/pull/17898))
+- Don't scan `.log` files for classes by default ([#17906](https://github.com/tailwindlabs/tailwindcss/pull/17906))
 
 ## [4.1.5] - 2025-04-30
 
diff --git a/crates/oxide/src/scanner/fixtures/ignored-extensions.txt b/crates/oxide/src/scanner/fixtures/ignored-extensions.txt
@@ -3,3 +3,4 @@ lock
 sass
 scss
 styl
+log
diff --git a/crates/oxide/src/scanner/mod.rs b/crates/oxide/src/scanner/mod.rs
@@ -16,10 +16,13 @@ use fxhash::{FxHashMap, FxHashSet};
 use ignore::{gitignore::GitignoreBuilder, WalkBuilder};
 use rayon::prelude::*;
 use std::collections::{BTreeMap, BTreeSet};
+use std::fs::OpenOptions;
+use std::io::{self, Write};
 use std::path::{Path, PathBuf};
 use std::sync::{self, Arc, Mutex};
 use std::time::SystemTime;
 use tracing::event;
+use tracing_subscriber::fmt::writer::BoxMakeWriter;
 
 // @source "some/folder";               // This is auto source detection
 // @source "some/folder/**/*";          // This is auto source detection
@@ -35,18 +38,67 @@ static SHOULD_TRACE: sync::LazyLock<bool> = sync::LazyLock::new(
     || matches!(std::env::var("DEBUG"), Ok(value) if value.eq("*") || (value.contains("tailwindcss:oxide") && !value.contains("-tailwindcss:oxide"))),
 );
 
+fn dim(input: &str) -> String {
+    format!("\u{001b}[2m{input}\u{001b}[22m")
+}
+
+fn blue(input: &str) -> String {
+    format!("\u{001b}[34m{input}\u{001b}[39m")
+}
+
+fn highlight(input: &str) -> String {
+    format!("{}{}{}", dim(&blue("`")), blue(input), dim(&blue("`")))
+}
+
 fn init_tracing() {
     if !*SHOULD_TRACE {
         return;
     }
 
+    let file_path = format!("tailwindcss-{}.log", std::process::id());
+    let file = OpenOptions::new()
+        .create(true)
+        .append(true)
+        .open(&file_path)
+        .unwrap_or_else(|_| panic!("Failed to open {file_path}"));
+
+    let file_path = Path::new(&file_path);
+    let absolute_file_path = dunce::canonicalize(file_path)
+        .unwrap_or_else(|_| panic!("Failed to canonicalize {file_path:?}"));
+    eprintln!(
+        "{} Writing debug info to: {}\n",
+        dim("[DEBUG]"),
+        highlight(absolute_file_path.as_path().to_str().unwrap())
+    );
+
+    let file = Arc::new(Mutex::new(file));
+
+    let writer: BoxMakeWriter = BoxMakeWriter::new({
+        let file = file.clone();
+        move || Box::new(MutexWriter(file.clone())) as Box<dyn Write + Send>
+    });
+
     _ = tracing_subscriber::fmt()
         .with_max_level(tracing::Level::INFO)
         .with_span_events(tracing_subscriber::fmt::format::FmtSpan::ACTIVE)
+        .with_writer(writer)
+        .with_ansi(false)
         .compact()
         .try_init();
 }
 
+struct MutexWriter(Arc<Mutex<std::fs::File>>);
+
+impl Write for MutexWriter {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        self.0.lock().unwrap().write(buf)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        self.0.lock().unwrap().flush()
+    }
+}
+
 #[derive(Debug, Clone)]
 pub enum ChangedContent {
     File(PathBuf, String),
@@ -394,7 +446,10 @@ impl Scanner {
 fn read_changed_content(c: ChangedContent) -> Option<Vec<u8>> {
     let (content, extension) = match c {
         ChangedContent::File(file, extension) => match std::fs::read(&file) {
-            Ok(content) => (content, extension),
+            Ok(content) => {
+                event!(tracing::Level::INFO, "Reading {:?}", file);
+                (content, extension)
+            }
             Err(e) => {
                 event!(tracing::Level::ERROR, "Failed to read file: {:?}", e);
                 return None;
@@ -706,7 +761,11 @@ fn create_walker(sources: Sources) -> Option<WalkBuilder> {
 
             match (current_time, previous_time) {
                 (Some(current), Some(prev)) if prev == current => false,
-                _ => true,
+                _ => {
+                    event!(tracing::Level::INFO, "Discovering {:?}", path);
+
+                    true
+                }
             }
         }
     });
diff --git a/packages/@tailwindcss-cli/src/commands/build/index.ts b/packages/@tailwindcss-cli/src/commands/build/index.ts
@@ -67,6 +67,9 @@ async function handleError<T>(fn: () => T): Promise<T> {
 }
 
 export async function handle(args: Result<ReturnType<typeof options>>) {
+  eprintln(header())
+  eprintln()
+
   using I = new Instrumentation()
   DEBUG && I.start('[@tailwindcss/cli] (initial build)')
 
@@ -87,8 +90,6 @@ export async function handle(args: Result<ReturnType<typeof options>>) {
 
     // Ensure the provided `--input` exists.
     if (!existsSync(args['--input'])) {
-      eprintln(header())
-      eprintln()
       eprintln(`Specified input file ${highlight(relative(args['--input']))} does not exist.`)
       process.exit(1)
     }
@@ -97,8 +98,6 @@ export async function handle(args: Result<ReturnType<typeof options>>) {
   // Check if the input and output file paths are identical, otherwise return an
   // error to the user.
   if (args['--input'] === args['--output'] && args['--input'] !== '-') {
-    eprintln(header())
-    eprintln()
     eprintln(
       `Specified input file ${highlight(relative(args['--input']))} and output file ${highlight(relative(args['--output']))} are identical.`,
     )
@@ -328,8 +327,6 @@ export async function handle(args: Result<ReturnType<typeof options>>) {
   await write(output, args, I)
 
   let end = process.hrtime.bigint()
-  eprintln(header())
-  eprintln()
   eprintln(`Done in ${formatDuration(end - start)}`)
 }
 

-Original file line number
+Diff line change
 sass
 scss
 styl
 +log