R""( **Note:** this command's interface is based heavily around [*installables*](./nix.md#installables), which you may want to read about first (`nix --help`). # Examples * Get the build log of GNU Hello: ```console # nix log nixpkgs#hello ``` * Get the build log of a specific store path: ```console # nix log /nix/store/lmngj4wcm9rkv3w4dfhzhcyij3195hiq-thunderbird-52.2.1 ``` * Get a build log from a specific binary cache: ```console # nix log --store https://cache.nixos.org nixpkgs#hello ``` # Description This command prints the log of a previous build of the [*installable*](./nix.md#installables) on standard output. Nix looks for build logs in two places: * In the directory `/nix/var/log/nix/drvs`, which contains logs for locally built derivations. * In the binary caches listed in the `substituters` setting. Logs should be named `/log/`, where `store-path` is a derivation, e.g. `https://cache.nixos.org/log/dvmig8jgrdapvbyxb1rprckdmdqx08kv-hello-2.10.drv`. For non-derivation store paths, Nix will first try to determine the deriver by fetching the `.narinfo` file for this store path. )""