Russ Cox
@swtch.com
Definitely turning into one of my longest code reviews ever...
January 10, 2026 at 4:22 PM
Definitely turning into one of my longest code reviews ever...
Indeed. There are more posts to come, but this "digression post" was ready and it seemed appropriate to post today. Stay tuned!
January 10, 2026 at 3:48 PM
Indeed. There are more posts to come, but this "digression post" was ready and it seemed appropriate to post today. Stay tuned!
“Pulling a New Proof from Knuth's Fixed-Point Printer”
Happy 88th Birthday to Don Knuth!
And thanks again to @robpike.io for Ivy.
research.swtch.com/fp-knuth
Happy 88th Birthday to Don Knuth!
And thanks again to @robpike.io for Ivy.
research.swtch.com/fp-knuth
research!rsc: Pulling a New Proof from Knuth’s Fixed-Point Printer
research.swtch.com
January 10, 2026 at 2:30 PM
“Pulling a New Proof from Knuth's Fixed-Point Printer”
Happy 88th Birthday to Don Knuth!
And thanks again to @robpike.io for Ivy.
research.swtch.com/fp-knuth
Happy 88th Birthday to Don Knuth!
And thanks again to @robpike.io for Ivy.
research.swtch.com/fp-knuth
This was a fun conversation. Thanks to ACM Bytecast for having me on. learning.acm.org/bytecast/ep7...
In this episode of ACM ByteCast, Bruke Kifle hosts Russ Cox, Distinguished Engineer at Google.
In this episode of ACM ByteCast, Bruke Kifle hosts Russ Cox, Distinguished Engineer at Google.
learning.acm.org
December 10, 2025 at 1:48 PM
This was a fun conversation. Thanks to ACM Bytecast for having me on. learning.acm.org/bytecast/ep7...
Happy to see someone outside Google rebuild/verify Go toolchains. Thanks @agwa.name! www.agwa.name/blog/post/ve...
"So far, Source Spotter has successfully reproduced every toolchain since Go 1.21.0, for every architecture and operating system. As of publication time, that's 2,672 toolchains!"
"So far, Source Spotter has successfully reproduced every toolchain since Go 1.21.0, for every architecture and operating system. As of publication time, that's 2,672 toolchains!"
I'm Independently Verifying Go's Reproducible Builds
Introducing Source Spotter, a Go Checksum Database auditor and Go toolchain reproducer
www.agwa.name
October 30, 2025 at 5:15 PM
Happy to see someone outside Google rebuild/verify Go toolchains. Thanks @agwa.name! www.agwa.name/blog/post/ve...
"So far, Source Spotter has successfully reproduced every toolchain since Go 1.21.0, for every architecture and operating system. As of publication time, that's 2,672 toolchains!"
"So far, Source Spotter has successfully reproduced every toolchain since Go 1.21.0, for every architecture and operating system. As of publication time, that's 2,672 toolchains!"
Please send a CL updating x/review/git-codereview to work with this too (grep for auth.cookie).
September 30, 2025 at 12:58 AM
Please send a CL updating x/review/git-codereview to work with this too (grep for auth.cookie).
Reposted by Russ Cox
There is some chatter about a CA misissuing a certificate for 1.1.1.1.
This CA (crt.sh?caid=201916, only ~300 certs) is only trusted by the Microsoft root program and the eIDAS QWAC trusted list.
MS has not been actively managing their roots for years, and the EU wanted to push theirs on browsers.
This CA (crt.sh?caid=201916, only ~300 certs) is only trusted by the Microsoft root program and the eIDAS QWAC trusted list.
MS has not been actively managing their roots for years, and the EU wanted to push theirs on browsers.
Incident Report: Mis-issued Certificates for SAN iPAddress:1.1.1.1 by Fina RDC 2020
Thank you, Youfu, for bringing this to the community’s attention.
groups.google.com
September 3, 2025 at 8:03 PM
There is some chatter about a CA misissuing a certificate for 1.1.1.1.
This CA (crt.sh?caid=201916, only ~300 certs) is only trusted by the Microsoft root program and the eIDAS QWAC trusted list.
MS has not been actively managing their roots for years, and the EU wanted to push theirs on browsers.
This CA (crt.sh?caid=201916, only ~300 certs) is only trusted by the Microsoft root program and the eIDAS QWAC trusted list.
MS has not been actively managing their roots for years, and the EU wanted to push theirs on browsers.
Heading home from #GopherCon 2025 in NYC. As usual, many people asked how to get one of the amazing Go gopher Hawaiian shirts by Renee French. I've posted the details at github.com/rsc/gophersh.... (I know one person who has made pajama pants with the pattern. Socks might be nice too.) Enjoy!
August 29, 2025 at 4:02 PM
Heading home from #GopherCon 2025 in NYC. As usual, many people asked how to get one of the amazing Go gopher Hawaiian shirts by Renee French. I've posted the details at github.com/rsc/gophersh.... (I know one person who has made pajama pants with the pattern. Socks might be nice too.) Enjoy!
Reposted by Russ Cox
Side point: this demonstrates the benefits of plain text file formats. When @robpike.io implemented the coverage tool he made it emit a simple line-based text file that Russ could then manipulate with the ubiquitous Unix tools.
April 25, 2025 at 10:35 PM
Side point: this demonstrates the benefits of plain text file formats. When @robpike.io implemented the coverage tool he made it emit a simple line-based text file that Russ could then manipulate with the ubiquitous Unix tools.
That was my first thought but the files aren’t sorted the way comm needs.
April 26, 2025 at 11:09 AM
That was my first thought but the files aren’t sorted the way comm needs.
True enough, but ultimately the problem is some other code that did run and zigged instead of zagging to the code that didn't run. I tried to make that point point earlier ("may prompt useful questions about what logic led to them being skipped...").
April 25, 2025 at 4:30 PM
True enough, but ultimately the problem is some other code that did run and zigged instead of zagging to the code that didn't run. I tried to make that point point earlier ("may prompt useful questions about what logic led to them being skipped...").
Overall I think the plumber works pretty well. I wouldn't change much. Language-specific clicking has been replaced by LSPs, but general clicks like URLs, issue numbers, RFCs, email addresses, or phone numbers are still helpful.
April 25, 2025 at 3:56 PM
Overall I think the plumber works pretty well. I wouldn't change much. Language-specific clicking has been replaced by LSPs, but general clicks like URLs, issue numbers, RFCs, email addresses, or phone numbers are still helpful.
Use tabs instead.
Years ago, when I worked with someone who insisted on spaces, I wrote a little C program called tab that changed spaces to tabs for my editing; tab -u changed them back.
gist.github.com/rsc/78589f27...
Years ago, when I worked with someone who insisted on spaces, I wrote a little C program called tab that changed spaces to tabs for my editing; tab -u changed them back.
gist.github.com/rsc/78589f27...
April 25, 2025 at 3:54 PM
Use tabs instead.
Years ago, when I worked with someone who insisted on spaces, I wrote a little C program called tab that changed spaces to tabs for my editing; tab -u changed them back.
gist.github.com/rsc/78589f27...
Years ago, when I worked with someone who insisted on spaces, I wrote a little C program called tab that changed spaces to tabs for my editing; tab -u changed them back.
gist.github.com/rsc/78589f27...
Reposted by Russ Cox
Fifty Years of Open Source Software Supply Chain Security
We are all struggling with a massive shift that has happened in the past 10 or 20 years in the software industry. For decades, software reuse was only a lofty goal. Now it's very real.
queue.acm.org/detail.cfm?i...
@swtch.com
We are all struggling with a massive shift that has happened in the past 10 or 20 years in the software industry. For decades, software reuse was only a lofty goal. Now it's very real.
queue.acm.org/detail.cfm?i...
@swtch.com
Fifty Years of Open Source Software Supply Chain Security - ACM Queue
queue.acm.org
April 3, 2025 at 4:45 PM
Fifty Years of Open Source Software Supply Chain Security
We are all struggling with a massive shift that has happened in the past 10 or 20 years in the software industry. For decades, software reuse was only a lofty goal. Now it's very real.
queue.acm.org/detail.cfm?i...
@swtch.com
We are all struggling with a massive shift that has happened in the past 10 or 20 years in the software industry. For decades, software reuse was only a lofty goal. Now it's very real.
queue.acm.org/detail.cfm?i...
@swtch.com
Reposted by Russ Cox
With 8 minutes to go, @damienmiller.bsky.social sends me the only funny April Fool's joke of the day.
Notably because I was on the team of people writing the firewall rules for Rob Pike's plan 9 desktop at Google.
@tailscale.com fixes it (albeit ten years too late).
Notably because I was on the team of people writing the firewall rules for Rob Pike's plan 9 desktop at Google.
@tailscale.com fixes it (albeit ten years too late).
Tailscale Enterprise Plan 9 Support
Securely connect to anything on the internet with Tailscale. Built on WireGuard®️, Tailscale enables you to make finely configurable connections, secured end-to-end according to zero trust principles,...
tailscale.com
April 2, 2025 at 6:54 AM
With 8 minutes to go, @damienmiller.bsky.social sends me the only funny April Fool's joke of the day.
Notably because I was on the team of people writing the firewall rules for Rob Pike's plan 9 desktop at Google.
@tailscale.com fixes it (albeit ten years too late).
Notably because I was on the team of people writing the firewall rules for Rob Pike's plan 9 desktop at Google.
@tailscale.com fixes it (albeit ten years too late).
Reposted by Russ Cox
i was going to say it was hilarious but i wished it was real and then i realized it was
April 1, 2025 at 2:58 PM
i was going to say it was hilarious but i wished it was real and then i realized it was
Reposted by Russ Cox
I only respect april fools jokes that commit to the bit. This? This is commitment.
"Tailscale Enterprise Plan 9 Support"
tailscale.com/plan9
(A little thing I wrote and worked on over the past few weekends with @swtch.com)
tailscale.com/plan9
(A little thing I wrote and worked on over the past few weekends with @swtch.com)
tailscale.com
April 1, 2025 at 3:04 PM
I only respect april fools jokes that commit to the bit. This? This is commitment.
This was a lot of fun!
"Tailscale Enterprise Plan 9 Support"
tailscale.com/plan9
(A little thing I wrote and worked on over the past few weekends with @swtch.com)
tailscale.com/plan9
(A little thing I wrote and worked on over the past few weekends with @swtch.com)
tailscale.com
April 1, 2025 at 5:58 PM
This was a lot of fun!
Reposted by Russ Cox
"Tailscale Enterprise Plan 9 Support"
tailscale.com/plan9
(A little thing I wrote and worked on over the past few weekends with @swtch.com)
tailscale.com/plan9
(A little thing I wrote and worked on over the past few weekends with @swtch.com)
tailscale.com
April 1, 2025 at 1:24 PM
"Tailscale Enterprise Plan 9 Support"
tailscale.com/plan9
(A little thing I wrote and worked on over the past few weekends with @swtch.com)
tailscale.com/plan9
(A little thing I wrote and worked on over the past few weekends with @swtch.com)
Reposted by Russ Cox
If you want to take the time to write up a helpful report about them, sure. I wrote this one up because (1) I needed to document somewhere why my change was causing performance differences that it shouldn't have, and (2) the effect was quite significant in a real program.
February 27, 2025 at 9:27 PM
If you want to take the time to write up a helpful report about them, sure. I wrote this one up because (1) I needed to document somewhere why my change was causing performance differences that it shouldn't have, and (2) the effect was quite significant in a real program.
If I could post the explicit link, wait appropriately long, and then edit the comment to use an implicit link, then maybe email would have something useful and web would be even better, at least after the time delay.
But what is the time delay?
3/3
But what is the time delay?
3/3
January 13, 2025 at 6:34 PM
If I could post the explicit link, wait appropriately long, and then edit the comment to use an implicit link, then maybe email would have something useful and web would be even better, at least after the time delay.
But what is the time delay?
3/3
But what is the time delay?
3/3
I "fix" this by writing an explicit link [TITLE HERE "/hashtag/12345%5D(https" class="hover:underline text-blue-600 dark:text-sky-400 no-card-link">#12345](https), which shows the link number and title in both contexts, but that isn't as nice as the default web display, omits issue status, and so on.
2/3
2/3
January 13, 2025 at 6:34 PM
I "fix" this by writing an explicit link [TITLE HERE "/hashtag/12345%5D(https" class="hover:underline text-blue-600 dark:text-sky-400 no-card-link">#12345](https), which shows the link number and title in both contexts, but that isn't as nice as the default web display, omits issue status, and so on.
2/3
2/3