diff --git a/doc/manual/rl-next/print-value-in-coercion-error.md b/doc/manual/rl-next/print-value-in-coercion-error.md new file mode 100644 index 000000000000..046e4e3cf4ab --- /dev/null +++ b/doc/manual/rl-next/print-value-in-coercion-error.md @@ -0,0 +1,24 @@ +--- +synopsis: Coercion errors include the failing value +issues: #561 +prs: #9754 +--- + +The `error: cannot coerce a to a string` message now includes the value +which caused the error. + +Before: + +``` + error: cannot coerce a set to a string +``` + +After: + +``` + error: cannot coerce a set to a string: { aesSupport = «thunk»; + avx2Support = «thunk»; avx512Support = «thunk»; avxSupport = «thunk»; + canExecute = «thunk»; config = «thunk»; darwinArch = «thunk»; darwinMinVersion + = «thunk»; darwinMinVersionVariable = «thunk»; darwinPlatform = «thunk»; «84 + attributes elided»} +``` diff --git a/doc/manual/src/language/string-interpolation.md b/doc/manual/src/language/string-interpolation.md index e999b287b9c6..6e28d26646bc 100644 --- a/doc/manual/src/language/string-interpolation.md +++ b/doc/manual/src/language/string-interpolation.md @@ -189,7 +189,7 @@ If neither is present, an error is thrown. > "${a}" > ``` > -> error: cannot coerce a set to a string +> error: cannot coerce a set to a string: { } > > at «string»:4:2: > diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 0659a217393b..050a34e5b1e7 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -29,7 +29,6 @@ #include #include #include -#include #include #include @@ -2233,7 +2232,9 @@ BackedStringView EvalState::coerceToString( return std::move(*maybeString); auto i = v.attrs->find(sOutPath); if (i == v.attrs->end()) { - error("cannot coerce %1% to a string", showType(v)) + error("cannot coerce %1% to a string: %2%", + showType(v), + ValuePrinter(*this, v, errorPrintOptions)) .withTrace(pos, errorCtx) .debugThrow(); } @@ -2279,7 +2280,9 @@ BackedStringView EvalState::coerceToString( } } - error("cannot coerce %1% to a string", showType(v)) + error("cannot coerce %1% to a string: %2%", + showType(v), + ValuePrinter(*this, v, errorPrintOptions)) .withTrace(pos, errorCtx) .debugThrow(); } @@ -2639,7 +2642,7 @@ void EvalState::printStatistics() std::string ExternalValueBase::coerceToString(const Pos & pos, NixStringContext & context, bool copyMore, bool copyToStore) const { throw TypeError({ - .msg = hintfmt("cannot coerce %1% to a string", showType()) + .msg = hintfmt("cannot coerce %1% to a string: %2%", showType(), *this) }); } diff --git a/src/libexpr/print-ambiguous.cc b/src/libexpr/print-ambiguous.cc index 07c398dd25a6..521250cecdb8 100644 --- a/src/libexpr/print-ambiguous.cc +++ b/src/libexpr/print-ambiguous.cc @@ -1,6 +1,7 @@ #include "print-ambiguous.hh" #include "print.hh" #include "signals.hh" +#include "eval.hh" namespace nix { diff --git a/src/libexpr/print-options.hh b/src/libexpr/print-options.hh index 11ff9ae879eb..e03746ece44b 100644 --- a/src/libexpr/print-options.hh +++ b/src/libexpr/print-options.hh @@ -36,11 +36,17 @@ struct PrintOptions */ size_t maxDepth = std::numeric_limits::max(); /** - * Maximum number of attributes in an attribute set to print. + * Maximum number of attributes in attribute sets to print. + * + * Note that this is a limit for the entire print invocation, not for each + * attribute set encountered. */ size_t maxAttrs = std::numeric_limits::max(); /** * Maximum number of list items to print. + * + * Note that this is a limit for the entire print invocation, not for each + * list encountered. */ size_t maxListItems = std::numeric_limits::max(); /** @@ -49,4 +55,16 @@ struct PrintOptions size_t maxStringLength = std::numeric_limits::max(); }; +/** + * `PrintOptions` for unknown and therefore potentially large values in error messages, + * to avoid printing "too much" output. + */ +static PrintOptions errorPrintOptions = PrintOptions { + .ansiColors = true, + .maxDepth = 10, + .maxAttrs = 10, + .maxListItems = 10, + .maxStringLength = 1024 +}; + } diff --git a/src/libexpr/print.cc b/src/libexpr/print.cc index db26ed4c285c..702e4bfe8c10 100644 --- a/src/libexpr/print.cc +++ b/src/libexpr/print.cc @@ -7,6 +7,7 @@ #include "store-api.hh" #include "terminal.hh" #include "english.hh" +#include "eval.hh" namespace nix { @@ -19,7 +20,7 @@ void printElided( { if (ansiColors) output << ANSI_FAINT; - output << " «"; + output << "«"; pluralize(output, value, single, plural); output << " elided»"; if (ansiColors) @@ -36,7 +37,7 @@ printLiteralString(std::ostream & str, const std::string_view string, size_t max str << "\""; for (auto i = string.begin(); i != string.end(); ++i) { if (charsPrinted >= maxLength) { - str << "\""; + str << "\" "; printElided(str, string.length() - charsPrinted, "byte", "bytes", ansiColors); return str; } @@ -160,6 +161,8 @@ class Printer EvalState & state; PrintOptions options; std::optional seen; + size_t attrsPrinted = 0; + size_t listItemsPrinted = 0; void printRepeated() { @@ -278,7 +281,6 @@ class Printer else std::sort(sorted.begin(), sorted.end(), ImportantFirstAttrNameCmp()); - size_t attrsPrinted = 0; for (auto & i : sorted) { if (attrsPrinted >= options.maxAttrs) { printElided(sorted.size() - attrsPrinted, "attribute", "attributes"); @@ -306,7 +308,6 @@ class Printer output << "[ "; if (depth < options.maxDepth) { - size_t listItemsPrinted = 0; for (auto elem : v.listItems()) { if (listItemsPrinted >= options.maxListItems) { printElided(v.listSize() - listItemsPrinted, "item", "items"); @@ -485,6 +486,9 @@ class Printer void print(Value & v) { + attrsPrinted = 0; + listItemsPrinted = 0; + if (options.trackRepeated) { seen.emplace(); } else { @@ -501,4 +505,10 @@ void printValue(EvalState & state, std::ostream & output, Value & v, PrintOption Printer(output, state, options).print(v); } +std::ostream & operator<<(std::ostream & output, const ValuePrinter & printer) +{ + printValue(printer.state, output, printer.value, printer.options); + return output; +} + } diff --git a/src/libexpr/print.hh b/src/libexpr/print.hh index 40207d77773f..a8300264a300 100644 --- a/src/libexpr/print.hh +++ b/src/libexpr/print.hh @@ -9,11 +9,13 @@ #include -#include "eval.hh" #include "print-options.hh" namespace nix { +class EvalState; +struct Value; + /** * Print a string as a Nix string literal. * @@ -59,4 +61,21 @@ std::ostream & printIdentifier(std::ostream & o, std::string_view s); void printValue(EvalState & state, std::ostream & str, Value & v, PrintOptions options = PrintOptions {}); +/** + * A partially-applied form of `printValue` which can be formatted using `<<` + * without allocating an intermediate string. + */ +class ValuePrinter { + friend std::ostream & operator << (std::ostream & output, const ValuePrinter & printer); +private: + EvalState & state; + Value & value; + PrintOptions options; + +public: + ValuePrinter(EvalState & state, Value & value, PrintOptions options = PrintOptions {}) + : state(state), value(value), options(options) { } +}; + +std::ostream & operator<<(std::ostream & output, const ValuePrinter & printer); } diff --git a/tests/functional/ca/config.nix.in b/tests/functional/ca/config.nix.in deleted file mode 120000 index af24ddb30b01..000000000000 --- a/tests/functional/ca/config.nix.in +++ /dev/null @@ -1 +0,0 @@ -../config.nix.in \ No newline at end of file diff --git a/tests/functional/ca/config.nix.in b/tests/functional/ca/config.nix.in new file mode 100644 index 000000000000..00dc007e12fc --- /dev/null +++ b/tests/functional/ca/config.nix.in @@ -0,0 +1,30 @@ +let + contentAddressedByDefault = builtins.getEnv "NIX_TESTS_CA_BY_DEFAULT" == "1"; + caArgs = if contentAddressedByDefault then { + __contentAddressed = true; + outputHashMode = "recursive"; + outputHashAlgo = "sha256"; + } else {}; +in + +rec { + shell = "@bash@"; + + path = "@coreutils@"; + + system = "@system@"; + + shared = builtins.getEnv "_NIX_TEST_SHARED"; + + mkDerivation = args: + derivation ({ + inherit system; + builder = shell; + args = ["-e" args.builder or (builtins.toFile "builder-${args.name}.sh" '' + if [ -e "$NIX_ATTRS_SH_FILE" ]; then source $NIX_ATTRS_SH_FILE; fi; + eval "$buildCommand" + '')]; + PATH = path; + } // caArgs // removeAttrs args ["builder" "meta"]) + // { meta = args.meta or {}; }; +} diff --git a/tests/functional/dyn-drv/config.nix.in b/tests/functional/dyn-drv/config.nix.in deleted file mode 120000 index af24ddb30b01..000000000000 --- a/tests/functional/dyn-drv/config.nix.in +++ /dev/null @@ -1 +0,0 @@ -../config.nix.in \ No newline at end of file diff --git a/tests/functional/dyn-drv/config.nix.in b/tests/functional/dyn-drv/config.nix.in new file mode 100644 index 000000000000..00dc007e12fc --- /dev/null +++ b/tests/functional/dyn-drv/config.nix.in @@ -0,0 +1,30 @@ +let + contentAddressedByDefault = builtins.getEnv "NIX_TESTS_CA_BY_DEFAULT" == "1"; + caArgs = if contentAddressedByDefault then { + __contentAddressed = true; + outputHashMode = "recursive"; + outputHashAlgo = "sha256"; + } else {}; +in + +rec { + shell = "@bash@"; + + path = "@coreutils@"; + + system = "@system@"; + + shared = builtins.getEnv "_NIX_TEST_SHARED"; + + mkDerivation = args: + derivation ({ + inherit system; + builder = shell; + args = ["-e" args.builder or (builtins.toFile "builder-${args.name}.sh" '' + if [ -e "$NIX_ATTRS_SH_FILE" ]; then source $NIX_ATTRS_SH_FILE; fi; + eval "$buildCommand" + '')]; + PATH = path; + } // caArgs // removeAttrs args ["builder" "meta"]) + // { meta = args.meta or {}; }; +} diff --git a/tests/functional/lang/eval-fail-bad-string-interpolation-1.err.exp b/tests/functional/lang/eval-fail-bad-string-interpolation-1.err.exp index b461b2e02adf..5ae53034d187 100644 --- a/tests/functional/lang/eval-fail-bad-string-interpolation-1.err.exp +++ b/tests/functional/lang/eval-fail-bad-string-interpolation-1.err.exp @@ -5,4 +5,4 @@ error: | ^ 2| - error: cannot coerce a function to a string + error: cannot coerce a function to a string: «lambda @ /pwd/lang/eval-fail-bad-string-interpolation-1.nix:1:4» diff --git a/tests/functional/lang/eval-fail-bad-string-interpolation-3.err.exp b/tests/functional/lang/eval-fail-bad-string-interpolation-3.err.exp index 95f4c2460043..170a3d13233c 100644 --- a/tests/functional/lang/eval-fail-bad-string-interpolation-3.err.exp +++ b/tests/functional/lang/eval-fail-bad-string-interpolation-3.err.exp @@ -5,4 +5,4 @@ error: | ^ 2| - error: cannot coerce a function to a string + error: cannot coerce a function to a string: «lambda @ /pwd/lang/eval-fail-bad-string-interpolation-3.nix:1:5» diff --git a/tests/functional/lang/eval-fail-bad-string-interpolation-4.err.exp b/tests/functional/lang/eval-fail-bad-string-interpolation-4.err.exp index 4950f8ddb809..5119238d77d8 100644 --- a/tests/functional/lang/eval-fail-bad-string-interpolation-4.err.exp +++ b/tests/functional/lang/eval-fail-bad-string-interpolation-4.err.exp @@ -6,4 +6,4 @@ error: | ^ 10| - error: cannot coerce a set to a string + error: cannot coerce a set to a string: { a = { a = { a = { a = "ha"; b = "ha"; c = "ha"; d = "ha"; e = "ha"; f = "ha"; g = "ha"; h = "ha"; j = "ha"; }; «4294967295 attributes elided»}; «4294967294 attributes elided»}; «4294967293 attributes elided»} diff --git a/tests/unit/libexpr/error_traces.cc b/tests/unit/libexpr/error_traces.cc index 81498f65a3f8..6814654e2765 100644 --- a/tests/unit/libexpr/error_traces.cc +++ b/tests/unit/libexpr/error_traces.cc @@ -295,7 +295,7 @@ namespace nix { TEST_F(ErrorTraceTest, toPath) { ASSERT_TRACE2("toPath []", TypeError, - hintfmt("cannot coerce %s to a string", "a list"), + hintfmt("cannot coerce %s to a string: %s", "a list", "[ ]"), hintfmt("while evaluating the first argument passed to builtins.toPath")); ASSERT_TRACE2("toPath \"foo\"", @@ -309,7 +309,7 @@ namespace nix { TEST_F(ErrorTraceTest, storePath) { ASSERT_TRACE2("storePath true", TypeError, - hintfmt("cannot coerce %s to a string", "a Boolean"), + hintfmt("cannot coerce %s to a string: %s", "a Boolean", ANSI_CYAN "true" ANSI_NORMAL), hintfmt("while evaluating the first argument passed to 'builtins.storePath'")); } @@ -318,7 +318,7 @@ namespace nix { TEST_F(ErrorTraceTest, pathExists) { ASSERT_TRACE2("pathExists []", TypeError, - hintfmt("cannot coerce %s to a string", "a list"), + hintfmt("cannot coerce %s to a string: %s", "a list", "[ ]"), hintfmt("while realising the context of a path")); ASSERT_TRACE2("pathExists \"zorglub\"", @@ -332,7 +332,7 @@ namespace nix { TEST_F(ErrorTraceTest, baseNameOf) { ASSERT_TRACE2("baseNameOf []", TypeError, - hintfmt("cannot coerce %s to a string", "a list"), + hintfmt("cannot coerce %s to a string: %s", "a list", "[ ]"), hintfmt("while evaluating the first argument passed to builtins.baseNameOf")); } @@ -377,7 +377,7 @@ namespace nix { TEST_F(ErrorTraceTest, filterSource) { ASSERT_TRACE2("filterSource [] []", TypeError, - hintfmt("cannot coerce %s to a string", "a list"), + hintfmt("cannot coerce %s to a string: %s", "a list", "[ ]"), hintfmt("while evaluating the second argument (the path to filter) passed to 'builtins.filterSource'")); ASSERT_TRACE2("filterSource [] \"foo\"", @@ -1038,7 +1038,7 @@ namespace nix { TEST_F(ErrorTraceTest, toString) { ASSERT_TRACE2("toString { a = 1; }", TypeError, - hintfmt("cannot coerce %s to a string", "a set"), + hintfmt("cannot coerce %s to a string: %s", "a set", "{ a = " ANSI_CYAN "1" ANSI_NORMAL "; }"), hintfmt("while evaluating the first argument passed to builtins.toString")); } @@ -1057,7 +1057,7 @@ namespace nix { ASSERT_TRACE2("substring 0 3 {}", TypeError, - hintfmt("cannot coerce %s to a string", "a set"), + hintfmt("cannot coerce %s to a string: %s", "a set", "{ }"), hintfmt("while evaluating the third argument (the string) passed to builtins.substring")); ASSERT_TRACE1("substring (-3) 3 \"sometext\"", @@ -1070,7 +1070,7 @@ namespace nix { TEST_F(ErrorTraceTest, stringLength) { ASSERT_TRACE2("stringLength {} # TODO: context is missing ???", TypeError, - hintfmt("cannot coerce %s to a string", "a set"), + hintfmt("cannot coerce %s to a string: %s", "a set", "{ }"), hintfmt("while evaluating the argument passed to builtins.stringLength")); } @@ -1143,7 +1143,7 @@ namespace nix { ASSERT_TRACE2("concatStringsSep \"foo\" [ 1 2 {} ] # TODO: coerce to string is buggy", TypeError, - hintfmt("cannot coerce %s to a string", "an integer"), + hintfmt("cannot coerce %s to a string: %s", "an integer", ANSI_CYAN "1" ANSI_NORMAL), hintfmt("while evaluating one element of the list of strings to concat passed to builtins.concatStringsSep")); } @@ -1229,12 +1229,12 @@ namespace nix { ASSERT_TRACE2("derivationStrict { name = \"foo\"; builder = 1; system = {}; }", TypeError, - hintfmt("cannot coerce %s to a string", "a set"), + hintfmt("cannot coerce %s to a string: %s", "a set", "{ }"), hintfmt("while evaluating the attribute 'system' of derivation 'foo'")); ASSERT_TRACE2("derivationStrict { name = \"foo\"; builder = 1; system = 1; outputs = {}; }", TypeError, - hintfmt("cannot coerce %s to a string", "a set"), + hintfmt("cannot coerce %s to a string: %s", "a set", "{ }"), hintfmt("while evaluating the attribute 'outputs' of derivation 'foo'")); ASSERT_TRACE2("derivationStrict { name = \"foo\"; builder = 1; system = 1; outputs = \"drv\"; }", @@ -1279,17 +1279,17 @@ namespace nix { ASSERT_TRACE2("derivationStrict { name = \"foo\"; builder = 1; system = 1; outputs = \"out\"; args = [ {} ]; }", TypeError, - hintfmt("cannot coerce %s to a string", "a set"), + hintfmt("cannot coerce %s to a string: %s", "a set", "{ }"), hintfmt("while evaluating an element of the argument list")); ASSERT_TRACE2("derivationStrict { name = \"foo\"; builder = 1; system = 1; outputs = \"out\"; args = [ \"a\" {} ]; }", TypeError, - hintfmt("cannot coerce %s to a string", "a set"), + hintfmt("cannot coerce %s to a string: %s", "a set", "{ }"), hintfmt("while evaluating an element of the argument list")); ASSERT_TRACE2("derivationStrict { name = \"foo\"; builder = 1; system = 1; outputs = \"out\"; FOO = {}; }", TypeError, - hintfmt("cannot coerce %s to a string", "a set"), + hintfmt("cannot coerce %s to a string: %s", "a set", "{ }"), hintfmt("while evaluating the attribute 'FOO' of derivation 'foo'")); } diff --git a/tests/unit/libexpr/value/print.cc b/tests/unit/libexpr/value/print.cc index 98131112e40b..c4264a38dbc4 100644 --- a/tests/unit/libexpr/value/print.cc +++ b/tests/unit/libexpr/value/print.cc @@ -370,7 +370,7 @@ TEST_F(ValuePrintingTests, ansiColorsStringElided) v.mkString("puppy"); test(v, - ANSI_MAGENTA "\"pup\"" ANSI_FAINT " «2 bytes elided»" ANSI_NORMAL, + ANSI_MAGENTA "\"pup\" " ANSI_FAINT "«2 bytes elided»" ANSI_NORMAL, PrintOptions { .ansiColors = true, .maxStringLength = 3 @@ -756,7 +756,7 @@ TEST_F(ValuePrintingTests, ansiColorsAttrsElided) vAttrs.mkAttrs(builder.finish()); test(vAttrs, - "{ one = " ANSI_CYAN "1" ANSI_NORMAL "; " ANSI_FAINT " «1 attribute elided»" ANSI_NORMAL "}", + "{ one = " ANSI_CYAN "1" ANSI_NORMAL "; " ANSI_FAINT "«1 attribute elided»" ANSI_NORMAL "}", PrintOptions { .ansiColors = true, .maxAttrs = 1 @@ -769,7 +769,7 @@ TEST_F(ValuePrintingTests, ansiColorsAttrsElided) vAttrs.mkAttrs(builder.finish()); test(vAttrs, - "{ one = " ANSI_CYAN "1" ANSI_NORMAL "; " ANSI_FAINT " «2 attributes elided»" ANSI_NORMAL "}", + "{ one = " ANSI_CYAN "1" ANSI_NORMAL "; " ANSI_FAINT "«2 attributes elided»" ANSI_NORMAL "}", PrintOptions { .ansiColors = true, .maxAttrs = 1 @@ -793,7 +793,7 @@ TEST_F(ValuePrintingTests, ansiColorsListElided) vList.bigList.size = 2; test(vList, - "[ " ANSI_CYAN "1" ANSI_NORMAL " " ANSI_FAINT " «1 item elided»" ANSI_NORMAL "]", + "[ " ANSI_CYAN "1" ANSI_NORMAL " " ANSI_FAINT "«1 item elided»" ANSI_NORMAL "]", PrintOptions { .ansiColors = true, .maxListItems = 1 @@ -806,7 +806,7 @@ TEST_F(ValuePrintingTests, ansiColorsListElided) vList.bigList.size = 3; test(vList, - "[ " ANSI_CYAN "1" ANSI_NORMAL " " ANSI_FAINT " «2 items elided»" ANSI_NORMAL "]", + "[ " ANSI_CYAN "1" ANSI_NORMAL " " ANSI_FAINT "«2 items elided»" ANSI_NORMAL "]", PrintOptions { .ansiColors = true, .maxListItems = 1