problems with XLSX files containing PNGs, pivot tables or SmartArt

Describe the bug I have discovered that the XLSX custom adapters in ripgrep-all do not work reliably with some Excel files, specifically those containing SmartArt, pivot tables, or more than one (sometimes two) embedded PNG images.

The binaries that power these custom XLSX adapters (e.g. xlsx2csv, in2csv, and my own custom testing adapter based on xlsxgrep) work correctly when used independently on the same files. This suggests that the issue may lie in rga-preproc, possibly in how it handles adapter output or how that output is passed between the adapters and ripgrep-all itself.

Some of my observations:

• ripgrep-all threw the following error when using any of my three custom XLSX adapters on Excel files that contained additional custom Excel metadata:

rg: Downloads/PNG_Excel.xlsx: preprocessor command failed: '"/opt/homebrew/bin/rga-preproc" "Downloads/PNG_Excel.xlsx"': 
-------------------------------------------------------------------------------
/Users/Downloads/PNG_Excel.xlsx adapter: in2csv_xlsx
/Users/Downloads/PNG_Excel.xlsx.txt adapter: postprocprefix
Error: copying adapter output to stdout

Caused by:
    Broken pipe (os error 32)
-------------------------------------------------------------------------------

• The in2csv-based adapter triggered the same error on Excel files containing more than one PNG image.
• The xlsx2csv-based adapter failed on Excel files with pivot tables.
• Both adapters failed on Excel files containing SmartArt.

In all cases, running the same binaries manually (outside of ripgrep-all) on the problematic files produced correct and complete output, without errors.

To Reproduce Run rga with the custom XLSX adapters listed here: https://github.com/phiresky/ripgrep-all/discussions/categories/show-your-adapter on an Excel file containing SmartArt, pivot tables, or multiple embedded PNG images.

Run command: rga --rga-adapters=xlsx2csv -il . "ProblematicFile.xlsx"

Output

rg: Downloads/PNG_Excel.xlsx: preprocessor command failed: '"/opt/homebrew/bin/rga-preproc" "Downloads/PNG_Excel.xlsx"': 
-------------------------------------------------------------------------------
/Users/Downloads/PNG_Excel.xlsx adapter: in2csv_xlsx
/Users/Downloads/PNG_Excel.xlsx.txt adapter: postprocprefix
Error: copying adapter output to stdout

Caused by:
    Broken pipe (os error 32)
-------------------------------------------------------------------------------

Screenshots If applicable, add screenshots to help explain your problem.

Operating System and Version macOS Tahoe 26.0.1 arm64

Output of rga --version ripgrep-all 0.10.9