I?ve been holding off upgrading to MacOS 26 for many reasons, most related to yet-unsubstantiated concerns about R. Because it?s a new ABI, I suspect the process would be similar to a major/minor release in R: update the compile chain then re-install all packages. Is there a strong recommendation for or against this upgrade? Are there safe or at least less-risky pathways for upgrading the OS? Is R-devel regularly tested against 26? Are there known unresolved problems, such as ?package xyz does not currently work?? FTR: I?m currently on macos 15.7.4 using R-4.5.2, and there is nothing inherently broken. I don?t have a /need/ to upgrade to 26 atm but fear at some point that some tool I use (be it Parallels or something else) may eventually require 26 for some or all of the desired functionality. I?m just planning ahead (and holding back two colleagues, also on macos-15.7). Thank you! Bill ​
macos 26 considerations
7 messages · biii+rsigm@c m@iii@g oii 8p@wexpress@com, Bill Evans, Gábor Csárdi +1 more
On 2026-02-22 10:40 a.m., Bill Evans via R-SIG-Mac wrote:
I?ve been holding off upgrading to MacOS 26 for many reasons, most related to yet-unsubstantiated concerns about R. Because it?s a new ABI, I suspect the process would be similar to a major/minor release in R: update the compile chain then re-install all packages. Is there a strong recommendation for or against this upgrade? Are there safe or at least less-risky pathways for upgrading the OS? Is R-devel regularly tested against 26? Are there known unresolved problems, such as ?package xyz does not currently work?? FTR: I?m currently on macos 15.7.4 using R-4.5.2, and there is nothing inherently broken. I don?t have a /need/ to upgrade to 26 atm but fear at some point that some tool I use (be it Parallels or something else) may eventually require 26 for some or all of the desired functionality. I?m just planning ahead (and holding back two colleagues, also on macos-15.7).
I upgraded in the fall, and found that XQuartz didn't work, and its maintainer had stopped working on it. Since I was planning some work on rgl that needed XQuartz, I downgraded and I'm still on Sequoia 15.7.2. You should be aware that downgrading isn't easy: you need to create a bootable external disk, reformat your main drive and restore from a backup. I did it and didn't lose anything, but it wasted a day or so, during which I wondered whether my backups were really as complete as I hoped they were. Duncan Murdoch
I am 26.2 and everything works fine, no need to reinstall anything, except maybe xquartz, which sometimes needs a reinstall after an update. But xquartz works fine as well. Gabor On Sun, Feb 22, 2026 at 4:40?PM Bill Evans via R-SIG-Mac
<r-sig-mac at r-project.org> wrote:
I?ve been holding off upgrading to MacOS 26 for many reasons, most
related to yet-unsubstantiated concerns about R. Because it?s a new ABI,
I suspect the process would be similar to a major/minor release in R:
update the compile chain then re-install all packages. Is there a strong
recommendation for or against this upgrade? Are there safe or at least
less-risky pathways for upgrading the OS? Is R-devel regularly tested
against 26? Are there known unresolved problems, such as ?package xyz
does not currently work??
FTR: I?m currently on macos 15.7.4 using R-4.5.2, and there is nothing
inherently broken. I don?t have a /need/ to upgrade to 26 atm but fear
at some point that some tool I use (be it Parallels or something else)
may eventually require 26 for some or all of the desired functionality.
I?m just planning ahead (and holding back two colleagues, also on
macos-15.7).
Thank you!
Bill
​
[[alternative HTML version deleted]]
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Thank you Prof Murdoch, that?s the context I was looking for. When
xquartz did not work for you in Tahoe, did you try homebrew or macports?
?xorg-server? and ?xinit? packages? The pair is a documented alternative
to xquartz, and if I believe what I read, those are supposed to work on
tahoe.
Some follow-on discussions for the crowd:
1.
Does there already exist or can we make an FAQ or caution-page for
upgrading to tahoe? I suspect I?m not the only one who has
considered taking the upgrade, and since downgrading is not easy
(likely ?not possible? for some), I think having a reference to this
on |mac.r-project.org| would be a ?Really Good Thing (tm)?.
2.
I believe XQuartz is for displaying the plot canvas when not using
RStudio or Positron. If we can?t have xquartz, what else are we
losing? As an incomplete alternative, for many plots one could use
|httpgd| (if/when they fix some bugs) or other ?immediate?
file-based rendering, though I think this does not work for |rgl|
(perhaps others).
3.
The webpage says /?R 4.6.0 CRAN arm64 builds use macOS 14?/, which
further concerns me wrt compatibility and package availability. I
know it?s a complicated topic, perhaps it?s too soon to say with
authority that tahoe is going to be safe for R and for compiled
binary packages.
This is likely related to Xcode and the MacOS SDK; I believe Tahoe
?really wants? Xcode 26 and the 26 SDK, and I believe (no refs atm)
that older versions can be problematic on Tahoe. I understand
backward compatibility is always a concern, perhaps that is why the
dev build is targeting macos 14, xcode 14.3, and 14.4 SDK. There are
a lot of talented people working tirelessly (and often thanklessly)
on this process, the more I learn the more I am thoroughly grateful
for their knowledge and efforts.
Is there yet a clear pathway for advancing to more up-to-date
versions? Or is it still murky and peppering the devs with questions
like this is just accelerating their ?early retirement??
4.
Are all of my xcode/sdk questions above ?moot? when using the
RStudio or Positron IDEs? They are not (afaict) using x11 to render
their plots, though I?m not sure how they show rgl-based plots.
Thanks all, I appreciate your time.
Bill
On 2026-02-22 08:50, Duncan Murdoch wrote:
On 2026-02-22 10:40 a.m., Bill Evans via R-SIG-Mac wrote:
I?ve been holding off upgrading to MacOS 26 for many reasons, most related to yet-unsubstantiated concerns about R. Because it?s a new ABI, I suspect the process would be similar to a major/minor release in R: update the compile chain then re-install all packages. Is there a strong recommendation for or against this upgrade? Are there safe or at least less-risky pathways for upgrading the OS? Is R-devel regularly tested against 26? Are there known unresolved problems, such as ?package xyz does not currently work?? FTR: I?m currently on macos 15.7.4 using R-4.5.2, and there is nothing inherently broken. I don?t have a /need/ to upgrade to 26 atm but fear at some point that some tool I use (be it Parallels or something else) may eventually require 26 for some or all of the desired functionality. I?m just planning ahead (and holding back two colleagues, also on macos-15.7).
I upgraded in the fall, and found that XQuartz didn't work, and its maintainer had stopped working on it.? Since I was planning some work on rgl that needed XQuartz, I downgraded and I'm still on Sequoia 15.7.2. You should be aware that downgrading isn't easy:? you need to create a bootable external disk, reformat your main drive and restore from a backup.? I did it and didn't lose anything, but it wasted a day or so, during which I wondered whether my backups were really as complete as I hoped they were. Duncan Murdoch
​
Thank you Prof Murdoch, that?s the context I was looking for. When xquartz did not work for you in Tahoe, did you try homebrew or macports? ?xorg-server? and ?xinit? packages? The pair is a documented alternative to xquartz, and if I believe what I read, those are supposed to work on tahoe.
On 2026-02-22 09:15, G?bor Cs?rdi wrote:
I am 26.2 and everything works fine, no need to reinstall anything, except maybe xquartz, which sometimes needs a reinstall after an update. But xquartz works fine as well.
Very interesting! I?m curious about the difference in your experience and Prof Murdoch?s, perhaps the rgl-dev work is more nuanced than you?ve tested in your use of xquartz? I wonder if xorg-server would be any better (since it is quite a bit newer) for that. Thanks all, I appreciate your time. Bill
On 2026-02-22 08:50, Duncan Murdoch wrote:
On 2026-02-22 10:40 a.m., Bill Evans via R-SIG-Mac wrote:
I?ve been holding off upgrading to MacOS 26 for many reasons, most related to yet-unsubstantiated concerns about R. Because it?s a new ABI, I suspect the process would be similar to a major/minor release in R: update the compile chain then re-install all packages. Is there a strong recommendation for or against this upgrade? Are there safe or at least less-risky pathways for upgrading the OS? Is R-devel regularly tested against 26? Are there known unresolved problems, such as ?package xyz does not currently work?? FTR: I?m currently on macos 15.7.4 using R-4.5.2, and there is nothing inherently broken. I don?t have a /need/ to upgrade to 26 atm but fear at some point that some tool I use (be it Parallels or something else) may eventually require 26 for some or all of the desired functionality. I?m just planning ahead (and holding back two colleagues, also on macos-15.7).
I upgraded in the fall, and found that XQuartz didn't work, and its maintainer had stopped working on it.? Since I was planning some work on rgl that needed XQuartz, I downgraded and I'm still on Sequoia 15.7.2. You should be aware that downgrading isn't easy:? you need to create a bootable external disk, reformat your main drive and restore from a backup.? I did it and didn't lose anything, but it wasted a day or so, during which I wondered whether my backups were really as complete as I hoped they were. Duncan Murdoch
​
On Sun, Feb 22, 2026 at 6:25?PM Bill Evans via R-SIG-Mac
<r-sig-mac at r-project.org> wrote:
[...]
On 2026-02-22 09:15, G?bor Cs?rdi wrote:
I am 26.2 and everything works fine, no need to reinstall anything, except maybe xquartz, which sometimes needs a reinstall after an update. But xquartz works fine as well.
Very interesting! I?m curious about the difference in your experience and Prof Murdoch?s, perhaps the rgl-dev work is more nuanced than you?ve tested in your use of xquartz? I wonder if xorg-server would be any better (since it is quite a bit newer) for that.
I don't use rgl or x11, so I indeed only ran `x11(); plot(1:10)` for a minimal test, and opengl indeed does not seem to work if I try library(rgl). If I just install xorg-server and xinit, then R does not find the X server when loading the R_X11 dll. G.
On 2026-02-22 12:15 p.m., Bill Evans wrote:
Thank you Prof Murdoch, that?s the context I was looking for. When xquartz did not work for you in Tahoe, did you try homebrew or macports? ?xorg-server? and ?xinit? packages? The pair is a documented alternative to xquartz, and if I believe what I read, those are supposed to work on tahoe.
No, I didn't try those. I was on a very tight schedule, and I didn't have time to experiment. But from what Gabor wrote, maybe Xquartz is working again with the latest Tahoe. For what it's worth, I did a quick search today and found this advice against Tahoe for some neuroimaging people: https://discuss.afni.nimh.nih.gov/t/re-macos-tahoe-and-xquartz-issues-for-afni-users/9227 As of Jan 21 they were still advising against the upgrade, though some of their problems had been addressed. Duncan
Some follow-on discussions for the crowd:
1.
Does there already exist or can we make an FAQ or caution-page for
upgrading to tahoe? I suspect I?m not the only one who has
considered taking the upgrade, and since downgrading is not easy
(likely ?not possible? for some), I think having a reference to this
on |mac.r-project.org| would be a ?Really Good Thing (tm)?.
2.
I believe XQuartz is for displaying the plot canvas when not using
RStudio or Positron. If we can?t have xquartz, what else are we
losing? As an incomplete alternative, for many plots one could use |
httpgd| (if/when they fix some bugs) or other ?immediate? file-based
rendering, though I think this does not work for |rgl| (perhaps others).
3.
The webpage says /?R 4.6.0 CRAN arm64 builds use macOS 14?/, which
further concerns me wrt compatibility and package availability. I
know it?s a complicated topic, perhaps it?s too soon to say with
authority that tahoe is going to be safe for R and for compiled
binary packages.
This is likely related to Xcode and the MacOS SDK; I believe Tahoe
?really wants? Xcode 26 and the 26 SDK, and I believe (no refs atm)
that older versions can be problematic on Tahoe. I understand
backward compatibility is always a concern, perhaps that is why the
dev build is targeting macos 14, xcode 14.3, and 14.4 SDK. There are
a lot of talented people working tirelessly (and often thanklessly)
on this process, the more I learn the more I am thoroughly grateful
for their knowledge and efforts.
Is there yet a clear pathway for advancing to more up-to-date
versions? Or is it still murky and peppering the devs with questions
like this is just accelerating their ?early retirement??
4.
Are all of my xcode/sdk questions above ?moot? when using the
RStudio or Positron IDEs? They are not (afaict) using x11 to render
their plots, though I?m not sure how they show rgl-based plots.
Thanks all, I appreciate your time.
Bill
On 2026-02-22 08:50, Duncan Murdoch wrote:
On 2026-02-22 10:40 a.m., Bill Evans via R-SIG-Mac wrote:
I?ve been holding off upgrading to MacOS 26 for many reasons, most related to yet-unsubstantiated concerns about R. Because it?s a new ABI, I suspect the process would be similar to a major/minor release in R: update the compile chain then re-install all packages. Is there a strong recommendation for or against this upgrade? Are there safe or at least less-risky pathways for upgrading the OS? Is R-devel regularly tested against 26? Are there known unresolved problems, such as ?package xyz does not currently work?? FTR: I?m currently on macos 15.7.4 using R-4.5.2, and there is nothing inherently broken. I don?t have a /need/ to upgrade to 26 atm but fear at some point that some tool I use (be it Parallels or something else) may eventually require 26 for some or all of the desired functionality. I?m just planning ahead (and holding back two colleagues, also on macos-15.7).
I upgraded in the fall, and found that XQuartz didn't work, and its maintainer had stopped working on it.? Since I was planning some work on rgl that needed XQuartz, I downgraded and I'm still on Sequoia 15.7.2. You should be aware that downgrading isn't easy:? you need to create a bootable external disk, reformat your main drive and restore from a backup.? I did it and didn't lose anything, but it wasted a day or so, during which I wondered whether my backups were really as complete as I hoped they were. Duncan Murdoch
​