Why is `git send-email` so awful in 2017?

I set myself out to send my first Linux kernel patch using my new Dell XPS13 as someone contacted me to ask for help supporting a new it87 chip in the gpio-it87 driver I originally contributed.

Writing the (trivial) patch was easy, since they had some access to the datasheet, but then the problem came to figure out how to send it over to the right mailing list. And that took me significantly more time than it should have, and significantly more time than writing the patch, too.

So why is it that git send-email is still so awful, in 2017?

So the first problem is that the only way you can send these email is either through a sendmail-compatible interface, which is literally an interface older than me (by two years), or through SMTP directly (this is even older, as RFC 821 is from 1982 — but being a protocol, that I do expect). The SMTP client has at least support for TLS, provided you have the right Perl modules installed, and authentication, though it does not support more complex forms of authentication such as Gmail’s XOAUTH2 protocol (ignore the fact it says IMAP, it is meant to apply to both IMAP and SMTP).

Instead, the documented (in the man page) approach for users with Gmail and 2FA enabled – which should be anybody who wants to contribute to the Linux kernel! – is to request an app-specific password and saving it through the credential store mechanism. Unfortunately the default credential store just stores it as unencrypted plaintext. Instead there are a number of credential helpers you can use, either using Gnome Keyring or libsecret, and so on.

Microsoft maintains and releases its own Credential Manager which is designed to support multi-factor login to a number of separate services, including GitHub and BitBucket. Thank you, Microsoft, although it appears to only be available for Windows, sigh!

Unfortunately it does not appear there is a good credential helper for either KWallet or LastPass which would have been interesting — to a point of course. I would probably never give LastPass an app-specific password to my Google account, as it would defeat my point of not keeping that particular password in a password manager.

So I start looking around and I find that there is a tool called keyring2 which supposedly has kwallet support, though on Arch Linux it does not appear to be working (the kwallet support, not the tool, which appear to work fine with Gnome Keyring). So I checked out the issues, and the defaulting to gnome-keyring is known, and there is a feature request for a LastPass backend. That sounds promising, right? Except that the author suggests building it as a separate library, which makes sense to a point. Unfortunately the implicit reference to their keyrings.alt (which does not appear to support KDE/Plasma), drove me away from the whole thing. Why?

License is indicated in the project metadata (typically one or more of the Trove classifiers). For more details, see this explanation.

And the explanation then says:

I acknowledge that there might be some subtle legal ramifications with not having the license text with the source code. I’ll happily revisit this issue at such a point that legal disputes become a real issue.

Which effectively reads to me as “I know what the right thing to do is, but it cramps my style and I don’t want to do it.” The fact that there have been already people pointing out the problem, and the fact that multiple issues have been reported and then marked as duplicate of this master issue, should speak clearly enough.

In particular, if I wanted to contribute anything to these repositories I would have no hope to do so but in my free time, if I decide to apply for a personal project request, as these projects are likely considered “No License” by the sheer lack of copyright information or licenses.

Now, I know I have not been the best person for this as well. But at least for glucometerutils I have made sure that each file lists its license clearly, and the license is spelt out in the README file too. And I will be correcting some of my past mistakes at some point soon, together with certain other mistakes.

But okay, so this is not a viable option. What else remains to use? Well, turns out that there is an actual FreeDesktop.org specification, or at least a draft, which appears to have been last touched seven years ago, for a common API to share between GNOME and KWallet, and for which there are a few other implementations already out there… but the current KWallet does not support it, and the replacement (KSecretService) appears to be stalled/gone/deprecated. And that effectively means that you can’t use that either.

Now, on Gentoo I know I can use msmtp integrated with KWallet and the sendmail interface, but I’m not sure if in Arch Linux it would work correctly. After all I even found out that I needed to install a number of Perl modules manually, because they are not listed in the dependencies and I don’t think I want to screw with PKGBUILD files if I can avoid it.

So at the end of the day, why is git send-email so awful? I guess the answer is that in so many years we still don’t have a half-decent, secure replacement for sending email. We need what they would now call “disruptive technology”, akin to how SSH killed Telnet, to bring up a decent way to send email, or at least submit Git patches to the Linux kernel. Sigh.

Update 2020-08-29: if you are reading this to try to make sense on how to use git send-email with Gmail or GSuite, you may want to instead turn to the sendgmail binary released in the gmail-oauth2-tools repository. It’s not great, particularly as the upstream maintainer has been very non-responsive, even when I was a co-worker, and it’s not the easiest thing to setup either (it needs you to have a Google Cloud account and enable the right API key), but it does work. If you feel like forking this, and merging the requisite pull requests, and release it as its own application, please be my guest. I’m not using Gmail anymore myself, so…