Philip McGrath

It looks like this error is from `net/sendurl`'s use of `shell-execute` on Windows.

I've cherry-picked 153ff9acb7ad63717a50bb26cd5aaa053870c666 as e673c71 on top of f90bcc15b87e16651c67404a3e3231c366f712bc from the `release` branch, and I can confirm that it fixes the test failure. Is it possible to get this in...

I'm sorry to report that my latest build has hit a variety of new errors: the log is at [gfpb5mlpv8cdirfhaz4m8xqbhxvhvi-chez-scheme-for-racket-9.5.9.2.drv.gz](https://github.com/racket/racket/files/9175070/gfpb5mlpv8cdirfhaz4m8xqbhxvhvi-chez-scheme-for-racket-9.5.9.2.drv.gz), which is from building https://github.com/LiberalArtist/racket/commit/d1f5d402c9f850cb8dcc0039b7562a888ce504f1.

I tried enabling Chez tests again, and they're passing now with https://github.com/LiberalArtist/racket/commit/d52bbde2ae635d944faea56b36efaaff9c87775e. I have no idea why they're passing, but I have no idea why they weren't working before, either,...

It happened again! This time I was building https://github.com/LiberalArtist/racket/commit/477d6f9d2872d4fe3839693f14594960110f1719: the build log is [5gj58rk5drcfgfvskx2kq1zcclcdpjad-chez-scheme-for-racket-9.5.9.2.drv.gz](https://github.com/racket/racket/files/9239273/5gj58rk5drcfgfvskx2kq1zcclcdpjad-chez-scheme-for-racket-9.5.9.2.drv.gz). I'll see if I can reproduce the failure consistently.

I think you're right that it's a problem with paths. I remembered that I had switched to an out-of-source build for Racket's Chez sometime since 8.5. Just now, I was...

> I'll next try an in-source build with [153ff9a](https://github.com/racket/racket/commit/153ff9acb7ad63717a50bb26cd5aaa053870c666) cherry-picked on top of 8.6: if that works, I can try to debug the out-of-source build after getting the 8.6 release...

This seems to be fixed in 8.7.

I've dropped the second commit. Supplying `CC_FOR_BUILD' isn't causing any difficulty for me here, and I agree that keeping Zuo as self-contained as reasonably possible seems good.

I was thinking about this again and thought I should leave a pointer here to https://github.com/racket/racket/issues/3834#issuecomment-866941280 by @mflatt, about a similar way we're currently using `'lib-search-dirs` in Guix's packaging of...