stdenv: perform checks only when evaluating .drv and .out

This pushes check-meta evaluation to derivation evaluation step, leaving all other
attributes accessible.

Before this commit:

> $ HOME=/homeless-shelter NIX_PATH=nixpkgs=$(pwd) nix-instantiate --eval --strict ./default.nix -A xen --argstr system aarch64-linux
> Package ‘xen-4.5.5’ in pkgs/applications/virtualization/xen/generic.nix:226 is not supported on ‘aarch64-linux’, refusing to evaluate.

as expected

> $ HOME=/homeless-shelter NIX_PATH=nixpkgs=$(pwd) nix-instantiate --eval --strict ./default.nix -A xen.name --argstr system aarch64-linux
> Package ‘xen-4.5.5’ in pkgs/applications/virtualization/xen/generic.nix:226 is not supported on ‘aarch64-linux’, refusing to evaluate.

> $ HOME=/homeless-shelter NIX_PATH=nixpkgs=$(pwd) nix-instantiate --eval --strict ./default.nix -A xen.meta.description --argstr system aarch64-linux
> Package ‘xen-4.5.5’ in pkgs/applications/virtualization/xen/generic.nix:226 is not supported on ‘aarch64-linux’, refusing to evaluate.

which is unfortunate since its impossible to use packages in autogenerated
documentation on all platforms.

After this commit:

> $ HOME=/homeless-shelter NIX_PATH=nixpkgs=$(pwd) nix-instantiate --eval --strict ./default.nix -A xen --argstr system aarch64-linux

still fails

> $ HOME=/homeless-shelter NIX_PATH=nixpkgs=$(pwd) nix-instantiate --eval --strict ./default.nix -A xen.name --argstr system aarch64-linux
> "xen-4.5.5"

> $ HOME=/homeless-shelter NIX_PATH=nixpkgs=$(pwd) nix-instantiate --eval --strict ./default.nix -A xen.meta.description --argstr system aarch64-linux
> "Xen hypervisor and related components (vanilla)"
This commit is contained in:
Jan Malakhovski 2017-12-25 17:38:45 +00:00
parent b1ca8517ee
commit d1d5ecb3bf
2 changed files with 29 additions and 29 deletions

View file

@ -1,6 +1,5 @@
# Extend a derivation with checks for brokenness, license, etc. Throw a
# descriptive error when the check fails; return `derivationArg` otherwise.
# Note: no dependencies are checked in this step.
# Checks derivation meta and attrs for problems (like brokenness,
# licenses, etc).
{ lib, config, system, meta, derivationArg, mkDerivationArg }:
@ -196,13 +195,11 @@ let
{ valid = false; reason = "unknown-meta"; errormsg = "has an invalid meta attrset:${lib.concatMapStrings (x: "\n\t - " + x) res}"; }
else { valid = true; };
# Throw an error if trying to evaluate an non-valid derivation
validityCondition =
let v = checkValidity attrs;
in if !v.valid
then handleEvalIssue (removeAttrs v ["valid"])
else true;
validity = checkValidity attrs;
in
assert validityCondition;
derivationArg
in validity // {
# Throw an error if trying to evaluate an non-valid derivation
handled = if !validity.valid
then handleEvalIssue (removeAttrs validity ["valid"])
else true;
}

View file

@ -182,6 +182,14 @@ rec {
outputs = outputs';
} else { }));
validity = import ./check-meta.nix {
inherit lib config meta derivationArg;
mkDerivationArg = attrs;
# Nix itself uses the `system` field of a derivation to decide where
# to build it. This is a bit confusing for cross compilation.
inherit (stdenv) system;
};
# The meta attribute is passed in the resulting attribute set,
# but it's not part of the actual derivation, i.e., it's not
# passed to the builder and is not a dependency. But since we
@ -207,21 +215,16 @@ rec {
in
lib.addPassthru
(derivation (import ./check-meta.nix
{
inherit lib config meta derivationArg;
mkDerivationArg = attrs;
# Nix itself uses the `system` field of a derivation to decide where
# to build it. This is a bit confusing for cross compilation.
inherit (stdenv) system;
}))
( {
overrideAttrs = f: mkDerivation (attrs // (f attrs));
inherit meta passthru;
} //
# Pass through extra attributes that are not inputs, but
# should be made available to Nix expressions using the
# derivation (e.g., in assertions).
passthru);
lib.extendDerivation
validity.handled
({
overrideAttrs = f: mkDerivation (attrs // (f attrs));
inherit meta passthru;
} //
# Pass through extra attributes that are not inputs, but
# should be made available to Nix expressions using the
# derivation (e.g., in assertions).
passthru)
(derivation derivationArg);
}