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let inherit (lib) nv nvs; in
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# composableDerivation basically mixes these features:
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# - provides shortcuts for "options" such as "--enable-foo" and adding
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# buildInputs, see php example
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# It predates styles which are common today, such as
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# * mkDerivation.override feature
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# * overrideDerivation (lib/customization.nix)
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# Some of the most more important usage examples (which could be rewritten if it was important):
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# A minimal example illustrating most features would look like this:
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# let base = composableDerivation { (fixed : let inherit (fixed.fixed) name in {
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# preConfigre = "echo ${name}";
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# # attention, "name" attr is missing, thus you cannot instantiate "base".
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# # These all add name attribute, thus you can instantiate those:
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# v1 = base.merge ({ name = "foo-add-B"; buildInputs = [B]; }); // B gets merged into buildInputs
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# v2 = base.merge ({ name = "mix-in-pre-configure-lines" preConfigre = ""; });
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# v3 = base.replace ({ name = "foo-no-A-only-B;" buildInputs = [B]; });
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# So yes, you can think about it being something like nixos modules, and
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# you'd be merging "features" in one at a time using .merge or .replace
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# Thanks Shea for telling me that I rethink the documentation ..
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# * its complicated to understand
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# * some "features" such as exact merge behaviour are burried in mergeAttrBy
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# and defaultOverridableDelayableArgs assuming the default behaviour does
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# the right thing in the common case
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# * Eelco once said using such fix style functions are slow to evaluate
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# * Too quick & dirty. Hard to understand for others. The benefit was that
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# you were able to create a kernel builder like base derivation and replace
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# / add patches the way you want without having to declare function arguments
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# declaring "optional featuers" is modular. For instance:
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# configureFlags = ["--with-curl=${curl}" "--with-curlwrappers"];
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# buildInputs = [curl openssl];
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# (Example taken from PHP)
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# alternative styles / related features:
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# * Eg see function supporting building the kernel
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# * versionedDerivation (discussion about this is still going on - or ended)
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# * mkDerivation.override
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# * using { .., *Support ? false }: like configurable options.
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# To find those examples use grep
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# To sum up: It exists for historical reasons - and for most commonly used
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# tasks the alternatives should be used
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# If you have questions about this code ping Marc Weber.
mkDerivation ? pkgs.stdenv.mkDerivation,
pyrox.dev