Failure to apply patch regression in rattler-build 0.42.1

[traversaro]

In conda-forge/torchcodec-feedstock#15 I experienced a regression in a patch that used to apply cleanly in 0.41.0, probably due to the change in the patching implementation.

To reproduce:

git clone https://github.com/conda-forge/torchcodec-feedstock
cd torchcodec-feedstock
git checkout d23287ce540e074ee6a5d4db3f50912abc261c27
# this fails
pixi global install rattler-build==0.42.1
rattler-build build --recipe-dir ./recipe/ -m ./.ci_support/linux_64_cuda_compiler_versionNonepython3.12.____cpython.yaml
# this works
pixi global install rattler-build==0.41.0
rattler-build build --recipe-dir ./recipe/ -m ./.ci_support/linux_64_cuda_compiler_versionNonepython3.12.____cpython.yaml

Example log:

traversaro@IITBMP014LW012:~/torchcodec-feedstock$ pixi global install rattler-build==0.42.1
Global environments as specified in '/home/traversaro/.pixi/manifests/pixi-global.toml'
└── rattler-build: 0.42.1 (already installed)
    └─ exposes: rattler-build
traversaro@IITBMP014LW012:~/torchcodec-feedstock$ rattler-build build --recipe-dir ./recipe/ -m ./.ci_support/linux_64_cuda_compiler_versionNonepython3.12.____cpython.yaml

 ╭─ Finding outputs from recipe
 │ Loading variant config file: "./.ci_support/linux_64_cuda_compiler_versionNonepython3.12.____cpython.yaml"
 │ Found 2 variants
 │
 │ Build variant: torchcodec-0.3.0-cpu_py312_h1c85667_0
 │
 │ ╭───────────────────────┬────────────────────╮
 │ │ Variant               ┆ Version            │
 │ ╞═══════════════════════╪════════════════════╡
 │ │ build_platform        ┆ "linux-64"         │
 │ │ c_compiler            ┆ "gcc"              │
 │ │ c_compiler_version    ┆ "13"               │
 │ │ c_stdlib              ┆ "sysroot"          │
 │ │ c_stdlib_version      ┆ "2.17"             │
 │ │ channel_sources       ┆ "conda-forge"      │
 │ │ channel_targets       ┆ "conda-forge main" │
 │ │ cuda_compiler         ┆ "None"             │
 │ │ cuda_compiler_version ┆ "None"             │
 │ │ cxx_compiler          ┆ "gxx"              │
 │ │ cxx_compiler_version  ┆ "13"               │
 │ │ ffmpeg                ┆ "7"                │
 │ │ libtorch              ┆ "2.6"              │
 │ │ python                ┆ "3.12.* *_cpython" │
 │ │ pytorch               ┆ "2.6"              │
 │ │ target_platform       ┆ "linux-64"         │
 │ ╰───────────────────────┴────────────────────╯
 │
 │ Build variant: torchcodec-tests-0.3.0-cpu_py312_h31c50d3_0
 │
 │ ╭───────────────────────┬──────────────────────────────╮
 │ │ Variant               ┆ Version                      │
 │ ╞═══════════════════════╪══════════════════════════════╡
 │ │ channel_sources       ┆ "conda-forge"                │
 │ │ channel_targets       ┆ "conda-forge main"           │
 │ │ cuda_compiler_version ┆ "None"                       │
 │ │ python                ┆ "3.12.* *_cpython"           │
 │ │ target_platform       ┆ "linux-64"                   │
 │ │ torchcodec            ┆ "0.3.0 cpu_py312_h1c85667_0" │
 │ ╰───────────────────────┴──────────────────────────────╯
 │
 ╰─────────────────── (took 0 seconds)

 ╭─ Running build for recipe: torchcodec-0.3.0-cpu_py312_h1c85667_0
 │
 │ ╭─ Fetching source code
 │ │ Fetching source from url: https://github.com/pytorch/torchcodec/archive/refs/tags/v0.3.0.tar.gz
 │ │ Downloaded file from https://github.com/pytorch/torchcodec/archive/refs/tags/v0.3.0.tar.gz
 │ │ Validated SHA256 values of the downloaded file!
 │ │ Extracting tar file to cache: /home/traversaro/torchcodec-feedstock/output/src_cache/v0_3_0_f535f184.tar.gz
 │ │ Copying source from url: /home/traversaro/torchcodec-feedstock/output/src_cache/v0_3_0_f535f184 to /home/traversaro/torchcodec-feedstock/output/bld/rattler-build_torchcodec_1748607064/work
 │ │ Applying patch: /home/traversaro/torchcodec-feedstock/recipe/use_strict_threshold_only_for_linux_x86_64.patch
 │ │
 │ ╰─────────────────── (took 4 seconds)
 │
 ╰─────────────────── (took 4 seconds)
Error:   × Failed to apply patch: use_strict_threshold_only_for_linux_x86_64.patch
  │ `git apply` failed with a combination of flags.
  │
  │ With the che command:
  │
  │     /usr/bin/git apply -p1 --verbose --ignore-space-change --ignore-whitespace /home/traversaro/torchcodec-feedstock/recipe/use_strict_threshold_only_for_linux_x86_64.patchThe output was:
  │
  │     Checking patch test/utils.py...
  │     error: while searching for:
  │     import json
  │     import os
  │     import pathlib
  │     import sys
  │
  │     from dataclasses import dataclass
  │
  │     error: patch failed: test/utils.py:2
  │     error: test/utils.py: patch does not apply
  │
  │
  │
  │ With the che command:
  │
  │     /usr/bin/git apply -p1 --verbose --ignore-space-change --ignore-whitespace --recount /home/traversaro/torchcodec-feedstock/recipe/use_strict_threshold_only_for_linux_x86_64.patchThe output was:
  │
  │     Checking patch test/utils.py...
  │     error: while searching for:
  │     import json
  │     import os
  │     import pathlib
  │     import sys
  │
  │     from dataclasses import dataclass
  │
  │     error: patch failed: test/utils.py:2
  │     error: test/utils.py: patch does not apply
  │
  │

traversaro@IITBMP014LW012:~/torchcodec-feedstock$ rm -rf output/
traversaro@IITBMP014LW012:~/torchcodec-feedstock$ pixi global install rattler-build==0.42.0
Error:   × Couldn't install rattler-build
  ├─▶ Failed to determine virtual packages for environment rattler-build
  ╰─▶ Cannot solve the request because of: No candidates were found for rattler-build ==0.42.0.


traversaro@IITBMP014LW012:~/torchcodec-feedstock$ pixi global install rattler-build==0.41.0
Global environments as specified in '/home/traversaro/.pixi/manifests/pixi-global.toml'
└── rattler-build: 0.41.0 (installed)
    └─ exposes: rattler-build
traversaro@IITBMP014LW012:~/torchcodec-feedstock$ rm -rf output/
traversaro@IITBMP014LW012:~/torchcodec-feedstock$ pixi global install rattler-build==0.41.0
Global environments as specified in '/home/traversaro/.pixi/manifests/pixi-global.toml'
└── rattler-build: 0.41.0 (already installed)
    └─ exposes: rattler-build
traversaro@IITBMP014LW012:~/torchcodec-feedstock$ rattler-build build --recipe-dir ./recipe/ -m ./.ci_support/linux_64_cuda_compiler_versionNonepython3.12.____cpython.yaml

 ╭─ Finding outputs from recipe
 │ Loading variant config file: "./.ci_support/linux_64_cuda_compiler_versionNonepython3.12.____cpython.yaml"
 │ Found 2 variants
 │
 │ Build variant: torchcodec-0.3.0-cpu_py312_h1c85667_0
 │
 │ ╭───────────────────────┬────────────────────╮
 │ │ Variant               ┆ Version            │
 │ ╞═══════════════════════╪════════════════════╡
 │ │ build_platform        ┆ "linux-64"         │
 │ │ c_compiler            ┆ "gcc"              │
 │ │ c_compiler_version    ┆ "13"               │
 │ │ c_stdlib              ┆ "sysroot"          │
 │ │ c_stdlib_version      ┆ "2.17"             │
 │ │ channel_sources       ┆ "conda-forge"      │
 │ │ channel_targets       ┆ "conda-forge main" │
 │ │ cuda_compiler         ┆ "None"             │
 │ │ cuda_compiler_version ┆ "None"             │
 │ │ cxx_compiler          ┆ "gxx"              │
 │ │ cxx_compiler_version  ┆ "13"               │
 │ │ ffmpeg                ┆ "7"                │
 │ │ libtorch              ┆ "2.6"              │
 │ │ python                ┆ "3.12.* *_cpython" │
 │ │ pytorch               ┆ "2.6"              │
 │ │ target_platform       ┆ "linux-64"         │
 │ ╰───────────────────────┴────────────────────╯
 │
 │ Build variant: torchcodec-tests-0.3.0-cpu_py312_h31c50d3_0
 │
 │ ╭───────────────────────┬──────────────────────────────╮
 │ │ Variant               ┆ Version                      │
 │ ╞═══════════════════════╪══════════════════════════════╡
 │ │ channel_sources       ┆ "conda-forge"                │
 │ │ channel_targets       ┆ "conda-forge main"           │
 │ │ cuda_compiler_version ┆ "None"                       │
 │ │ python                ┆ "3.12.* *_cpython"           │
 │ │ target_platform       ┆ "linux-64"                   │
 │ │ torchcodec            ┆ "0.3.0 cpu_py312_h1c85667_0" │
 │ ╰───────────────────────┴──────────────────────────────╯
 │
 ╰─────────────────── (took 0 seconds)

 ╭─ Running build for recipe: torchcodec-0.3.0-cpu_py312_h1c85667_0
 │
 │ ╭─ Fetching source code
 │ │ Fetching source from url: https://github.com/pytorch/torchcodec/archive/refs/tags/v0.3.0.tar.gz
 │ │ Downloaded file from https://github.com/pytorch/torchcodec/archive/refs/tags/v0.3.0.tar.gz
 │ │ Validated SHA256 values of the downloaded file!
 │ │ Extracting tar file to cache: /home/traversaro/torchcodec-feedstock/output/src_cache/v0_3_0_f535f184.tar.gz
 │ │ Copying source from url: /home/traversaro/torchcodec-feedstock/output/src_cache/v0_3_0_f535f184 to /home/traversaro/torchcodec-feedstock/output/bld/rattler-build_torchcodec_1748607090/work
 │ │ Applying patch: /home/traversaro/torchcodec-feedstock/recipe/use_strict_threshold_only_for_linux_x86_64.patch
 │ │ Applying patch: /home/traversaro/torchcodec-feedstock/recipe/657.patch
 │ │ Applying patch: /home/traversaro/torchcodec-feedstock/recipe/remove_werror.patch
 │ │
 │ ╰─────────────────── (took 3 seconds)

[wolfv]

I had a look and the problem is that the context in the patch says:

from dataclasses import dataclass

while in the code it now says:

from dataclasses import dataclass, foobar

Apparently, git does not deal with "fuzzy" context when applying patches, which is definitely a bummer.

I have locally extended diffy to also deal with fuzzy patches which we could use in #1676

We could also go back to use patch, and try to deal with CLRF issues by convertign files on the fly so that patch doesn't complain.

[traversaro]

Another reference to a patch that works fine with conda-build and fails with rattler-build 0.42.1 (and also with 0.41.0 in this case) can be found in conda-forge/mujoco-feedstock#85 :

 ╰─────────────────── (took 0 seconds)

 ╭─ Running build for recipe: libmujoco-3.3.2-hdb71998_2
 │
 │ ╭─ Fetching source code
 │ │ Fetching source from url: https://github.com/deepmind/mujoco/archive/refs/tags/3.3.2.tar.gz
 │ │ Downloaded file from https://github.com/deepmind/mujoco/archive/refs/tags/3.3.2.tar.gz
 │ │ Validated SHA256 values of the downloaded file!
 │ │ Extracting tar file to cache: /home/conda/feedstock_root/build_artifacts/src_cache/3_3_2_6ab615ad.tar.gz
 │ │ Copying source from url: /home/conda/feedstock_root/build_artifacts/src_cache/3_3_2_6ab615ad to /home/conda/feedstock_root/build_artifacts/bld/rattler-build_libmujoco_1749296266/work
 │ │ Applying patch: /home/conda/recipe_root/python_remove_avx.patch
 │ │
 │ ╰─────────────────── (took 5 seconds)
 │
 ╰─────────────────── (took 5 seconds)
Error:   × Failed to apply patch: python_remove_avx.patch
  │ `git apply` failed with a combination of flags.
  │ 
  │ With the che command:
  │ 	error: python/mujoco/CMakeLists.txt: patch does not apply
  │ 
  │