fix: set agentkeepalive freeSocketTimeout back to 15 seconds

[nlf]

this is a bit of a bandaid for the timeout issue that got introduced here recently. it makes our tests pass consistently again without timeouts, but it does also indicate some potential issues in minipass-fetch. or at least issues between minipass-fetch and agentkeepalive..

either way, this would be great to land to get our CI happy again and to stop causing other peoples tests to potentially fail (node-gyp saw this issue on their end as well) and we can move on to figuring out how to fix the root cause later.

[wraithgar]

attn @rvagg in re nodejs/node-gyp#2607. This looks too be the culprit. When this lands I'll make a pr into node-gyp

[darcyclarke]

Note: for those following along at home, the initial change in behavior was caused by agentkeepalive updating their default timeout values, to a significantly lower threshold, in a minor version (ie. make-fetch-happen picked up the latest version of that dep which had breaking changes) - ref. https://github.com/node-modules/agentkeepalive/blob/master/History.md#420--2021-12-31 (pr: node-modules/agentkeepalive#102 & commit: node-modules/agentkeepalive@f418c67).

As @nlf notes, we'll want to determine the root-cause/need for such a high threshold but that may take some time.

[rvagg]

any chance this might have windows-specific behaviours as well? we're still seeing high-frequency flakies on windows even with this change: https://github.com/nodejs/node-gyp/actions (can't be sure make-fetch-happen is to blame, but the regularity coincides with the v10 upgrade).

[nlf]

any chance this might have windows-specific behaviours as well? we're still seeing high-frequency flakies on windows even with this change: https://github.com/nodejs/node-gyp/actions (can't be sure make-fetch-happen is to blame, but the regularity coincides with the v10 upgrade).

yeah i saw that in the pull request i submitted. i'll keep digging. our own CI stabilized with this one so i was really hopeful it would take care of the problem for you too. i'll make sure we send you another pull request when we get it figured out