I'm opening this issue because:

• npm is crashing.
• npm is producing an incorrect install.
• npm is doing something I don't understand.
• Other (see below for feature requests):

What's going wrong?

Tarballs packed with npm 5.7.1 can no longer be explored with tools such as 7-Zip. The previous 5.6.0 had no issues. I experience this with Windows 7. WinZip, however, will open this appropriately.

I am logging the error here simply because npm 5.7.x is symptomatic, but the problem probably lies in the underlying tar package or its dependencies that were updated for the 5.7.0 release. I'll be glad to open an issue there if this could be confirmed.

I don't expect this issue to make it to the top of any lists as npm within itself works fine, but I do worry a little about whether there's anything non-standard now. When packing this very small package in the STRs with 5.6.0 and 5.7.1, I see large differences in size of the package, so perhaps there are some headers, etc. that may be different/missing? This was tested with 7-Zip's latest version, 18.01 (x64) / 2018-01-28 as well as a prior version.

How can the CLI team reproduce the problem?

1. md npm5pack && cd npm5pack && npm init -y && npm pack
2. Install 7-Zip.
3. Open npm5pack-1.0.0.tgz file with 7-Zip.
4. Attempt to open the contained .tar file. Expect to see this prompt with 5.7.x:

supporting information:

• npm -v prints: 5.7.1
• node -v prints: 8.9.4
• Windows, OS X/macOS, or Linux?: Windows 7 64-bit