Double whitespace breaks logging

[maxgriehl-web]

Bug Report

dvc repro: fails storing correct command in dvc.lock

Description

Some double spaces of dvc.yaml-commands are not stored in the dvc.lock-clone.
This happens if a command is too long, and gets formatted with an additional line break exactly at the double-space.

As a result, dvc status regards the stage as dirty, even directly after commiting or running it.

Reproduce

# 1. Create a new directory and initialize DVC
mkdir my-dir && cd my-dir
git init
dvc init

# 2. Create a dvc.yaml with lots of double spaces in the command
cat > dvc.yaml << 'EOF'
stages:
  test_stage:
    cmd: echo "lots"  "of"  "words"  "(too much"  "for"  "one"  "line)"  "with"  "lots"  "of"  "double-whitespace"  "between"  "the"  "parts" > output.txt
    outs:
      - output.txt
EOF

# 3. Run the stage to generate lock file
# (you can check in it that some double-space became a line-break!)
dvc repro

# 4. Check status - should be clean but shows "changed command"
dvc status

Expected

dvc status should regard everything as up-to-date.

Environment information

Output of dvc doctor:

$ dvc doctor

DVC version: 3.66.1 (pip)
-------------------------
Platform: Python 3.12.3 on Linux-6.14.0-119037-tuxedo-x86_64-with-glibc2.39
Subprojects:
        dvc_data = 3.18.2
        dvc_objects = 5.2.0
        dvc_render = 1.0.2
        dvc_task = 0.40.2
        scmrepo = 3.6.1
Supports:
        http (aiohttp = 3.13.3, aiohttp-retry = 2.9.1),
        https (aiohttp = 3.13.3, aiohttp-retry = 2.9.1),
        ssh (sshfs = 2025.11.0)
Config:
        Global: /home/maxg/.config/dvc
        System: /home/maxg/.config/kdedefaults/dvc
Cache types: hardlink, symlink
Cache directory: ext4 on /dev/mapper/system-root
Caches: local
Remotes: None
Workspace directory: ext4 on /dev/mapper/system-root
Repo: dvc, git
Repo.site_cache_dir: /var/tmp/dvc/repo/f919da52546ca06d0c807bb616433829

Additional Information:

Neither does dvc commit store the correct command.

Already started a discussion here #10933. But I guess, a bug-report is more appropriate.

[PreethamAnand]

Hi! I’ve set up DVC locally and I’m new to contributing.
Would it be okay if I take a look at fixing this issue?

[PreethamAnand]

I checked dvc.lock on Windows (PowerShell) using the current DVC dev build, and the command is stored minimally (cmd: only).
Even with long commands and double spaces, dvc status stays clean.
This suggests the issue may be OS/shell-specific (Linux/bash) or fixed in newer versions.
Let me know if you’d like me to test this on WSL/Linux or with an older DVC release.

[maxgriehl-web]

I checked dvc.lock on Windows (PowerShell) using the current DVC dev build, and the command is stored minimally (cmd: only). Even with long commands and double spaces, dvc status stays clean. This suggests the issue may be OS/shell-specific (Linux/bash) or fixed in newer versions. Let me know if you’d like me to test this on WSL/Linux or with an older DVC release.

Thanks for looking into this!

My colleague now tried it with WSL/Linux and gets the same error as I do on a pure Linux.
However, we didn't try any dev-builds. Only the newest 3.66.1 release.

[PreethamAnand]

Thanks for checking on WSL/Linux!

I can help narrow this down further.
Next, I’ll test this on:

• a DVC dev build (if available), and
• at least one older stable release (pre-3.6.x)

I’ll report back whether the double-whitespace line break issue
is a regression or long-standing behavior.

[skshetry]

@maxgriehl-web, this is a bug with ruamel.yaml that looks similar to https://sourceforge.net/p/ruamel-yaml/tickets/539/. It should have added an escape at the end before splitting the cmd.

from pathlib import Path

from ruamel.yaml import YAML

file = Path("dvc.yaml")
file.write_bytes(b"""
stages:
  test_stage:
    cmd: echo "lots"  "of"  "words"  "(too much"  "for"  "one"  "line)"  "with"  "lots"  "of"  "double-whitespace"  "between"  "the"  "parts" > output.txt
    outs:
    - output.txt
""")

y = YAML()
a = y.load(file)
print("Before dump:", a, sep="\n")
y.dump(a, file)

b = y.load(file)
print("After dump:", b, sep="\n")
print("Are they equal?", a == b)

Would you mind creating an issue upstream?

[skshetry]

I think this is related: https://sourceforge.net/p/ruamel-yaml/tickets/562/.