diff --git a/lib/modules.nix b/lib/modules.nix index 0869eae1982..c3c903c1dfa 100644 --- a/lib/modules.nix +++ b/lib/modules.nix @@ -323,16 +323,14 @@ rec { else mergeDefinitions loc opt.type defs'; - # Check whether the option is defined, and apply the ‘apply’ - # function to the merged value. This allows options to yield a - # value computed from the definitions. - value = - if !res.isDefined then - throw "The option `${showOption loc}' is used but not defined." - else if opt ? apply then - opt.apply res.mergedValue - else - res.mergedValue; + + # The value with a check that it is defined + valueDefined = if res.isDefined then res.mergedValue else + throw "The option `${showOption loc}' is used but not defined."; + + # Apply the 'apply' function to the merged value. This allows options to + # yield a value computed from the definitions + value = if opt ? apply then opt.apply valueDefined else valueDefined; in opt // { value = builtins.addErrorContext "while evaluating the option `${showOption loc}':" value;