prefix-dev
bug(variants): empty string variants not processed correctly
openblas-feedstock on 🎋 rattler [🎭⬆️ ] via 🧚 v0.48.2
❯ bat recipe/variants.yaml
───────┬────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
│ File: recipe/variants.yaml
───────┼────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
1 │ zip_keys:
2 │ - [SYMBOLSUFFIX, name_suffix, INTERFACE64]
3 │
4 │ # gcc 12 cannot handle `-mtune=native` on aarch,
5 │ # gcc 13 causes test failures on ppc
6 │ c_compiler_version:
7 │ - if: linux
8 │ then: 14
9 │ fortran_compiler_version:
10 │ - if: linux
11 │ then: 14
12 │
13 │ SYMBOLSUFFIX:
14 │ - ""
15 │ - if: not (win or aarch64)
16 │ then: "64_"
17 │
18 │ name_suffix:
19 │ - ""
20 │ - if: not (win or aarch64)
21 │ then: "-ilp64"
22 │
23 │ INTERFACE64:
24 │ - 0
25 │ - if: not (win or aarch64)
26 │ then: 1
27 │
28 │ USE_OPENMP:
29 │ - if: not osx
30 │ then: "0"
31 │ - "1"
───────┴────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
openblas-feedstock on 🎋 rattler [✘🎭?] via 🧚 v0.48.2
❯ pixi run rerender
...
Error: × Zip key elements do not all have same length: INTERFACE64
openblas-feedstock on 🎋 rattler [⬆️ ] via 🧚 v0.48.2 took 4s
❯ git diff
diff --git a/recipe/variants.yaml b/recipe/variants.yaml
index 8903f69..cfecacc 100644
--- a/recipe/variants.yaml
+++ b/recipe/variants.yaml
@@ -11,12 +11,12 @@ fortran_compiler_version:
then: 14
SYMBOLSUFFIX:
- - ""
+ - "foo"
- if: not (win or aarch64)
then: "64_"
name_suffix:
- - ""
+ - "bar"
- if: not (win or aarch64)
then: "-ilp64"
openblas-feedstock on 🎋 rattler [🔨⬆️ ] via 🧚 v0.48.2
❯ pixi run rerender
... // no error
Interesting. It's possible that we remove empty strings like this as if they would not exist.
It looks like the problem is in the initial parsing, by the time we get to https://github.com/prefix-dev/rattler-build/blob/5baeaf1bf3ea58e52c3a7b5ce3ffcb51711f1974/src/variant_config.rs#L572-L596 the empty strings are already dropped from the RenderedNodes:
2025-06-26T12:32:20.602508Z DEBUG Finding outputs from recipe: rattler_build::variant_config: "SYMBOLSUFFIX"
2025-06-26T12:32:20.602518Z DEBUG Finding outputs from recipe: rattler_build::variant_config: Sequence(
RenderedSequenceNode {
value: [
Scalar(
RenderedScalarNode {
value: "64_",
},
),
],
},
)
2025-06-26T12:32:20.602527Z DEBUG Finding outputs from recipe: rattler_build::variant_config: Some(
[
"64_",
],
)
2025-06-26T12:32:20.602532Z DEBUG Finding outputs from recipe: rattler_build::variant_config: "name_suffix"
2025-06-26T12:32:20.602535Z DEBUG Finding outputs from recipe: rattler_build::variant_config: Sequence(
RenderedSequenceNode {
value: [
Scalar(
RenderedScalarNode {
value: "-ilp64",
},
),
],
},
)
2025-06-26T12:32:20.602591Z DEBUG Finding outputs from recipe: rattler_build::variant_config: Some(
[
"-ilp64",
],
)
2025-06-26T12:32:20.602608Z DEBUG Finding outputs from recipe: rattler_build::variant_config: "INTERFACE64"
2025-06-26T12:32:20.602612Z DEBUG Finding outputs from recipe: rattler_build::variant_config: Sequence(
RenderedSequenceNode {
value: [
Scalar(
RenderedScalarNode {
value: "0",
},
),
Scalar(
RenderedScalarNode {
value: "1",
},
),
],
},
)
Possibly related:
Error:
× expected a scalar value.
╭─[recipe/recipe.yaml:11:17]
10 │ # ILP64_string: ${{ "" if SYMBOLSUFFIX != "64_" else " (ILP64 interface) " }}
11 │ ILP64_string: ""
· ─┬
· ╰── here
12 │ name_suffix: ""
╰────
help: `context` values must always be scalars (booleans, integers or strings) or uniform lists of scalars
switching to ${{ "" }} I see
yaml.constructor.ConstructorError: could not determine a constructor for the tag 'tag:yaml.org,2002:python/object/new:ruamel.yaml.scalarstring.DoubleQuotedScalarString'
EDIT: perhaps a different problem, I seem to see this after removing all ${{ "" }}
rattler-build build works fine with a local conda_build_config.yaml. However, rattler-build build -m fails with the following yaml dumped by rattler_build_conda_compat:
{'python': ['3.12'], 'numpy': ['1.26'], 'perl': ['5.26.2'], 'lua': ['5'], 'r_base': ['3.5'], 'cpu_optimization_target': ['nocona'], 'pin_run_as_build': {'python': {'min_pin': 'x.x', 'max_pin': 'x.x'}, 'r-base': {'min_pin': 'x.x', 'max_pin': 'x.x'}}, 'ignore_version': [], 'ignore_build_only_deps': ['python', 'numpy'], 'extend_keys': ['extend_keys', 'ignore_build_only_deps', 'pin_run_as_build', 'ignore_version'], 'cran_mirror': ['https://cran.r-project.org'], 'target_platform': ['linux-64'], 'c_compiler': ['gcc'], 'cxx_compiler': ['gxx'], 'fortran_compiler': ['gfortran'], 'c_compiler_version': ['14'], 'fortran_compiler_version': ['14'], 'SYMBOLSUFFIX': ['', '64_'], 'name_suffix': ['', '-ilp64'], 'INTERFACE64': ['0', '1'], 'USE_OPENMP': ['0', '1'], 'zip_keys': [['SYMBOLSUFFIX', 'name_suffix', 'INTERFACE64']], 'c_stdlib': ['sysroot'], 'c_stdlib_version': ['2.17']}
that yaml does include the empty string variants, so the problem is hit some time after rattler-build reading the yaml
correct at https://github.com/prefix-dev/rattler-build/blob/d18bacf0a77d5595b63256b6ad299b72e807089c/src/variant_config.rs#L258
ScalarNode {
value: "name_suffix",
}: Sequence(
SequenceNode {
value: [
Simple(
Scalar(
ScalarNode {
value: "",
},
),
),
Simple(
Scalar(
ScalarNode {
value: "-ilp64",
},
),
),
],
},
),
incorrect at https://github.com/prefix-dev/rattler-build/blob/d18bacf0a77d5595b63256b6ad299b72e807089c/src/variant_config.rs#L260
RenderedScalarNode {
value: "name_suffix",
}: Sequence(
RenderedSequenceNode {
value: [
Scalar(
RenderedScalarNode {
value: "-ilp64",
},
),
],
},
),
https://github.com/prefix-dev/rattler-build/blob/d18bacf0a77d5595b63256b6ad299b72e807089c/src/recipe/custom_yaml/rendered.rs#L663-L686 returns a Null node for an empty string variant.
@wolfv do you know if empty ScalarNodes are widely used as null values? https://github.com/prefix-dev/rattler-build/blob/d18bacf0a77d5595b63256b6ad299b72e807089c/src/recipe/custom_yaml.rs#L379-L382 seems to suggest that "null" would be an alternative.
implementing a stricter is_empty for RenderedScalarNode at gh-1764 fixes the immediate issue, but breaks other things
I closed the linked PR as I won't have time to look into it further, but maybe it was going in the right direction, so worth taking a look at if somebody else wants to try tackling this issue