48965506a1
`assert` has the annoying property that it dumps a lot of code at the user without the built in capability to display a nicer message. We have worked around this using `assertMsg` which would *additionally* display a nice message. We can do even better: By using `throw` we can make evaluation fail before assert draws its conclusions and prevent it from displaying the code making up the assert condition, so we get the nicer message of `throw` and the syntactical convenience of `assert`. Before: nix-repl> python.override { reproducibleBuild = true; stripBytecode = false; } trace: Deterministic builds require stripping bytecode. error: assertion (((lib).assertMsg (reproducibleBuild -> stripBytecode)) "Deterministic builds require stripping bytecode.") failed at /home/lukas/src/nix/nixpkgs/pkgs/development/interpreters/python/cpython/2.7/default.nix:45:1 After: nix-repl> python.override { reproducibleBuild = true; stripBytecode = false; } error: Deterministic builds require stripping bytecode. |
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doc | ||
lib | ||
maintainers | ||
modules | ||
tests | ||
COPYING | ||
default.nix | ||
README | ||
release-combined.nix | ||
release-small.nix | ||
release.nix |
*** NixOS *** NixOS is a Linux distribution based on the purely functional package management system Nix. More information can be found at https://nixos.org/nixos and in the manual in doc/manual.