[Bug]: Archiver `_compressFile` func leaks memory, leaks fd on error, and ignores errors.

[jglogan]

I have done the following

• I have searched the existing issues
• If possible, I've reproduced the issue using the 'main' branch of this project

Steps to reproduce

Should be observable using a build context with a large number of files.

Problem description

container build uses the Archiver type to create an archive of the build context to transfer to the builder VM.

The _compressFile function in Archiver writes a single member entry and its data to the archive. To this end it uses a 1 megabyte buffer, and an input stream. The implementation has several bugs though:

• Most seriously, it does not deallocate the buffer on exit from the function.
• The stream is not closed on a throwing error
• If an error occurs on a read from the stream (negative return value for error in contrast with zero for end of stream), the function silently exits instead of reporting an error.

Environment

- OS: 26
- Xcode: 26
- Container: main

Code of Conduct

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