From b7edc2099fffd7d54638122d2d9950e3d3a751f6 Mon Sep 17 00:00:00 2001 From: John Ericson Date: Wed, 6 Sep 2023 11:35:01 -0400 Subject: [PATCH] Improve derivation parsing - Don't assert: Derivation ATerms are not necessarily produced by Nix, and parsers should always throw graceful errors - Improve error message from `static void except(..)`, shows both what we expected and what we actually got. The intention is that we backport it, and then hopefully a few people might get slightly better errors if they try out new experimental drv files (for RFC 92) with an old version of Nix. --- src/libstore/derivations.cc | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/src/libstore/derivations.cc b/src/libstore/derivations.cc index dc32c3847de..43d3dc4a2a7 100644 --- a/src/libstore/derivations.cc +++ b/src/libstore/derivations.cc @@ -154,8 +154,9 @@ static void expect(std::istream & str, std::string_view s) { char s2[s.size()]; str.read(s2, s.size()); - if (std::string(s2, s.size()) != s) - throw FormatError("expected string '%1%'", s); + std::string_view s2View { s2, s.size() }; + if (s2View != s) + throw FormatError("expected string '%s', got '%s'", s, s2View); } @@ -223,7 +224,8 @@ static DerivationOutput parseDerivationOutput(const Store & store, const auto hashType = parseHashType(hashAlgo); if (hashS == "impure") { experimentalFeatureSettings.require(Xp::ImpureDerivations); - assert(pathS == ""); + if (pathS != "") + throw FormatError("impure derivation output should not specify output path"); return DerivationOutput::Impure { .method = std::move(method), .hashType = std::move(hashType), @@ -239,7 +241,8 @@ static DerivationOutput parseDerivationOutput(const Store & store, }; } else { experimentalFeatureSettings.require(Xp::CaDerivations); - assert(pathS == ""); + if (pathS != "") + throw FormatError("content-addressed derivation output should not specify output path"); return DerivationOutput::CAFloating { .method = std::move(method), .hashType = std::move(hashType),