I'm using intel's pin tool (pintool.org) and the boost library's filtering_stream in order to compress data before it goes to a file. I already have functioning code that does that, but at the very end of the execution of the target, right before the PIN_AddFiniFunction callback gets executed the stream of bytes in the compressed version ends (I assume this because the decompressed version is generated by subsequently opening another filtering_stream and using a zlib_decompressor and reading the entire compressed file out). I don't know why the stream ends early... This makes getting help kind of hard, because the files that are being produced are hundreds of megabytes, and differ by just a little kb. So even the diff is large, but I think the salient point is that the data included in the compressed/decompressed version is the same aside from the end. To make this easy for anybody helping, I've included a link to my repo where I've created a reproducible mini example, which should be able to be downloaded, built, and run without any hassel on the latest ubuntu: https://github.com/KennethAdamMiller/Boost-PinTool (It's a drop in replacement for debug trace; you just drop the appropriate files into the DebugTrace folder in your PIN_ROOT/source/tools/, then type make. There are very clear instructions! :) ) link to boost's filtering_stream: http://www.boost.org/doc/libs/1_54_0/libs/iostreams/doc/classes/filtering_st... After you build and run the tool, you should see debugtrace.out and decompressed.xml (the xml part I'm too lazy to change even as I type; it's just text). Go to the bottom of each, you can see that debugtrace.out ends with the line containing "eof" properly, but that the decompressed.xml does not... Can anybody tell me what the issue is? I'm quite certain that everything *should* have went into the FilteringStream that went into the ofstream... please help, I have no idea why it's terminating this way...