fix: backup extension on mac works now

[adthrasher]

With the previous solution, the bash argument wasn't being interpreted by the Mac sed version as a zero-length string. So it was appending the literal '' suffix and creating backup files. The fix is repetitive, but I can't get anything else to recognize the zero-length string properly.

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[a-frantz]

not ideal, but I'm fine with it

[adthrasher]

not ideal, but I'm fine with it

For the record, I tried inserting the whole argument via a substitution and just the space character. I was running short of ideas other than copy/paste the full command. I'm open to suggestions at this point.

inplace_arg="-i ''"
find . -not -path '.git' -a -type f -name '*.wdl' | xargs sed -Er $inplace_arg "s,$search_pattern,$replacement,g"

inplace_arg=" "
find . -not -path '.git' -a -type f -name '*.wdl' | xargs sed -Er -i${inplace_arg}'' "s,$search_pattern,$replacement,g"