diff options
| -rw-r--r-- | doc/manual/rl-next/better-errors-in-nix-repl.md | 40 | ||||
| -rw-r--r-- | src/libexpr/print.cc | 2 | ||||
| -rw-r--r-- | tests/unit/libexpr/value/print.cc | 44 |
3 files changed, 45 insertions, 41 deletions
diff --git a/doc/manual/rl-next/better-errors-in-nix-repl.md b/doc/manual/rl-next/better-errors-in-nix-repl.md new file mode 100644 index 000000000..4deaa8c70 --- /dev/null +++ b/doc/manual/rl-next/better-errors-in-nix-repl.md @@ -0,0 +1,40 @@ +--- +synopsis: Concise error printing in `nix repl` +prs: 9928 +--- + +Previously, if an element of a list or attribute set threw an error while +evaluating, `nix repl` would print the entire error (including source location +information) inline. This output was clumsy and difficult to parse: + +``` +nix-repl> { err = builtins.throw "uh oh!"; } +{ err = «error: + … while calling the 'throw' builtin + at «string»:1:9: + 1| { err = builtins.throw "uh oh!"; } + | ^ + + error: uh oh!»; } +``` + +Now, only the error message is displayed, making the output much more readable. +``` +nix-repl> { err = builtins.throw "uh oh!"; } +{ err = «error: uh oh!»; } +``` + +However, if the whole expression being evaluated throws an error, source +locations and (if applicable) a stack trace are printed, just like you'd expect: + +``` +nix-repl> builtins.throw "uh oh!" +error: + … while calling the 'throw' builtin + at «string»:1:1: + 1| builtins.throw "uh oh!" + | ^ + + error: uh oh! +``` + diff --git a/src/libexpr/print.cc b/src/libexpr/print.cc index fbd91e484..86eadfb17 100644 --- a/src/libexpr/print.cc +++ b/src/libexpr/print.cc @@ -407,7 +407,7 @@ private: { if (options.ansiColors) output << ANSI_RED; - output << "«" << e.msg() << "»"; + output << "«error: " << filterANSIEscapes(e.info().msg.str(), true) << "»"; if (options.ansiColors) output << ANSI_NORMAL; } diff --git a/tests/unit/libexpr/value/print.cc b/tests/unit/libexpr/value/print.cc index c4264a38d..c1de3a6a9 100644 --- a/tests/unit/libexpr/value/print.cc +++ b/tests/unit/libexpr/value/print.cc @@ -460,19 +460,7 @@ TEST_F(ValuePrintingTests, ansiColorsError) test(vError, ANSI_RED - "«" - ANSI_RED - "error:" - ANSI_NORMAL - "\n … while calling the '" - ANSI_MAGENTA - "throw" - ANSI_NORMAL - "' builtin\n\n " - ANSI_RED - "error:" - ANSI_NORMAL - " uh oh!»" + "«error: uh oh!»" ANSI_NORMAL, PrintOptions { .ansiColors = true, @@ -501,19 +489,7 @@ TEST_F(ValuePrintingTests, ansiColorsDerivationError) test(vAttrs, "{ drvPath = " ANSI_RED - "«" - ANSI_RED - "error:" - ANSI_NORMAL - "\n … while calling the '" - ANSI_MAGENTA - "throw" - ANSI_NORMAL - "' builtin\n\n " - ANSI_RED - "error:" - ANSI_NORMAL - " uh oh!»" + "«error: uh oh!»" ANSI_NORMAL "; type = " ANSI_MAGENTA @@ -527,19 +503,7 @@ TEST_F(ValuePrintingTests, ansiColorsDerivationError) test(vAttrs, ANSI_RED - "«" - ANSI_RED - "error:" - ANSI_NORMAL - "\n … while calling the '" - ANSI_MAGENTA - "throw" - ANSI_NORMAL - "' builtin\n\n " - ANSI_RED - "error:" - ANSI_NORMAL - " uh oh!»" + "«error: uh oh!»" ANSI_NORMAL, PrintOptions { .ansiColors = true, @@ -560,7 +524,7 @@ TEST_F(ValuePrintingTests, ansiColorsAssert) state.mkThunk_(v, &expr); test(v, - ANSI_RED "«" ANSI_RED "error:" ANSI_NORMAL " assertion '" ANSI_MAGENTA "false" ANSI_NORMAL "' failed»" ANSI_NORMAL, + ANSI_RED "«error: assertion 'false' failed»" ANSI_NORMAL, PrintOptions { .ansiColors = true, .force = true |