diff options
Diffstat (limited to 'doc/builders/fetchers.chapter.md')
| -rw-r--r-- | doc/builders/fetchers.chapter.md | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/doc/builders/fetchers.chapter.md b/doc/builders/fetchers.chapter.md index d9f22b06282..09a41cd9ce0 100644 --- a/doc/builders/fetchers.chapter.md +++ b/doc/builders/fetchers.chapter.md @@ -6,7 +6,7 @@ When using Nix, you will frequently need to download source code and other files Because fixed output derivations are _identified_ by their hash, a common mistake is to update a fetcher's URL or a version parameter, without updating the hash. **This will cause the old contents to be used.** So remember to always invalidate the hash argument. -For those who develop and maintain fetchers, a similar problem arises with changes to the implementation of a fetcher. These may cause a fixed output derivation to fail, but won't normally be caught by tests because the supposed output is already in the store or cache. For the purpose of testing, you can use a trick that is embodied by the [`invalidateFetcherByDrvHash`](#sec-pkgs-invalidateFetcherByDrvHash) function. It uses the derivation `name` to create a unique output path per fetcher implementation, defeating the caching precisely where it would be harmful. +For those who develop and maintain fetchers, a similar problem arises with changes to the implementation of a fetcher. These may cause a fixed output derivation to fail, but won't normally be caught by tests because the supposed output is already in the store or cache. For the purpose of testing, you can use a trick that is embodied by the [`invalidateFetcherByDrvHash`](#tester-invalidateFetcherByDrvHash) function. It uses the derivation `name` to create a unique output path per fetcher implementation, defeating the caching precisely where it would be harmful. ## `fetchurl` and `fetchzip` {#fetchurl} |