lix/doc/manual/src
Felix Uhl 3fefc2b284 Fix derivation load assertion errors
When loading a derivation from a JSON, malformed input would trigger
cryptic "assertion failed" errors. Simply replacing calls to `operator []`
with calls to `.at()` was not enough, as this would cause json.execptions
to be printed verbatim.

Display nice error messages instead and give some indication where the
error happened.

*Before:*

```
$ echo 4 | nix derivation add
error: [json.exception.type_error.305] cannot use operator[] with a string argument with number

$ nix derivation show nixpkgs#hello | nix derivation add
Assertion failed: (it != m_value.object->end()), function operator[], file /nix/store/8h9pxgq1776ns6qi5arx08ifgnhmgl22-nlohmann_json-3.11.2/include/nlohmann/json.hpp, line 2135.

$ nix derivation show nixpkgs#hello | jq '.[] | .name = 5' | nix derivation add
error: [json.exception.type_error.302] type must be string, but is object

$ nix derivation show nixpkgs#hello | jq '.[] | .outputs = { out: "/nix/store/8j3f8j-hello" }' | nix derivation add
error: [json.exception.type_error.302] type must be object, but is string

```

*After:*

```
$ echo 4 | nix derivation add
error: Expected JSON of derivation to be of type 'object', but it is of type 'number'

$ nix derivation show nixpkgs#hello | nix derivation add
error: Expected JSON object to contain key 'name' but it doesn't

$ nix derivation show nixpkgs#hello | jq '.[] | .name = 5' | nix derivation add
error: Expected JSON value to be of type 'string' but it is of type 'number'

$ nix derivation show nixpkgs#hello | jq '.[] | .outputs = { out: "/nix/store/8j3f8j-hello" }' | nix derivation add
error:
       … while reading key 'outputs'

       error: Expected JSON value to be of type 'object' but it is of type 'string'
```
2023-08-05 01:34:30 +02:00
..
advanced-topics rewrap lines to use one line per sentence 2023-05-31 01:32:03 +02:00
architecture Add description for file system objects (#8500) 2023-06-18 23:45:08 -04:00
command-ref list moving parts of channels 2023-07-19 10:26:25 +02:00
contributing fix broken links (#8722) 2023-07-20 17:58:14 +02:00
figures Move figures 2020-07-24 12:58:31 +02:00
installation nix actually needs c++20 now 2023-06-10 13:56:05 +02:00
language clarify wording on args@ default handling (#8596) 2023-07-19 13:07:07 +00:00
package-management remove the Channels section 2023-07-19 09:39:04 +02:00
protocols Apply suggestions from code review 2023-06-16 16:48:37 +02:00
release-notes Fix derivation load assertion errors 2023-08-05 01:34:30 +02:00
glossary.md Add description for file system objects (#8500) 2023-06-18 23:45:08 -04:00
introduction.md Convert short nix options to long ones 2023-05-17 08:10:30 +01:00
quick-start.md Update doc/manual/src/quick-start.md 2023-02-19 20:00:02 -05:00
SUMMARY.md.in Release notes 2023-07-24 17:19:31 +02:00