Like the poster in this Reddit thread, I am running low on drive space and would like to get rid of some of the older versions of GHC that Stack installed for me. (I have five versions installed and they’re taking up over 6 GB.) Is it safe just to remove the individual versions’ folders from ~/.stack/programs/x86_64-osx, or is there a better way?
Yes, deleting those directories is safe.
Related
I have on my computer (macOS High Sierra) multiple installations of the standard (Glasgow) Haskell compiler. The oldest one (as far as I can remember) is a minimal installation, while I obtained the most recent version form the "Platform" installer, something like five or six months ago. I'm trying to get rid of the whole ecosystem (ghc, stack, cabal, and friends), mostly because I don't know what tools I will be using in the case I'll plan to get back using the language.
So my questions are:
Where does the minimal/"Platform" installer installs Haskell and all related stuff?
How can one remove the whole Haskell language and all its components mentioned above (in the case of a "Platform" install, and even in the case of a minimal installation)?
EDIT: I've just remembered of the uninstall-hs command (see also here), should I run this instead of removing files manually?
I think I have come up with a solution and I'll answer the latter question first:
All the details I was looking for (what effectively is installed after launching the minimal / "Platform" installer, and, most importantly, where these guys were placed) can be found in the documentation welcome file at /Library/Haskell/Doc/Start.html. More precisely:
On Mac OS X, the Haskell Platform is installed in two major pieces: GHC and Haskell Platform. They are installed respectively in: /Library/Frameworks/GHC.framework and /Library/Haskell. Executables are symlinked in /usr/local/bin [...].
There are also another two or three directories in the home folder, namely ~/.ghc and ~/.stack.
As said in the OP, the script uninstall-hs done its work, showing a (at least I hope so) comprehensive list of all the files that constitutes the Haskell "sdk" actually installed.
Feel free to post your answers, I hope this post will be useful to the community.
I'm working with the Lean theorem prover and I would like to build features like those of stack and start building library caches. One thing that I'm unsure about is when to delete older packages in the cache. I could think that, if I have two versions of Lean installed, say 3.3.0 and 3.3.1, I could argue for keeping all the versions of all the packages that work on those. Since the Lean syntax moves fast, it is quite restrictive.
On the other hand, I could see keeping only 10 versions of any given package. This could be the 10 most recent versions or the 10 most recently requested versions.
I'd love to know some of the ideas considered in building stack and related tools.
stack keeps packages in cache forever. Or until you manually delete those packages. There's no snapshot garbage collection implemented in stack. So what you can only do is to manually call
rm -rf ~/.stack
to remove whole stack cache. It's in general good practice to do it periodically to remove outdated packages which were accumulated for some period of time. But make sure to backup .stack/global-project/stack.yaml if you changed it manually.
stack command which handles cache removal for you is under development:
https://github.com/commercialhaskell/stack/issues/133
sys/queue.h first appeared in 4.4BSD. Linux has included it in its distribution, but the version seems not up-to-date.
FreeBSD version implements singly-linked lists, singly-linked tail queues, lists and tail queues. Linux version implements lists, tail queues, and circular queues.
I installed libbsd-dev package in my Ubuntu PC and then found BSD version's sys/queue.h in /usr/include/bsd/sys/queue.h.
My questions:
Where can I find the Linux version of this header file?
What's the main difference between these two implementations? Is Linux version just a out-dated version of BSD's ?
They share the same ancestry, but it looks like any development that have been done in them diverged a long time ago.
If you want to use it in your project your best bet is to just copy the one you like the most into your project and use that. Don't depend on the system providing it for you. It's just a header file with a bunch of macros and doesn't need a library or any dependencies to work and as such isn't operating system specific at all. I usually take the one from OpenBSD for my projects.
Looks like Linux's version is seriously outdated. CIRCLEQ is (rather strongly) deprecated in BSDs since 2001, and it even got removed from the documentation, even if the implementation is still in queue.h. We are supposed to use TAILQ, which offers the same functionality with better performance/less problems/saner implementation.
Meanwhile, in Linux it's still even documented, but you can find changes in kconfig migrating from CIRCLEQ to TAILQ citing the BSD deprecation.
The concrete problem in CIRCLEQ seems to be that it uses a specific head, different to a list node, but which is anyway linked as a node; so the head pointer has to be kept around and checked at every node access to see if the node turns out to be the head. So there are 2 problems: the checks at every access, and the need to keep the head pointer at hand, taking registers or cache.
I am facing with the bug following:
https://bugzilla.samba.org/show_bug.cgi?id=4531
rsync will always get the older symlink of the other side overwrite
the newer one on the local side.
Wayne has suggested to use unison, however it is a non-developing old
project that I have suspect to use.
What can you suggest me for ?
My main aim is to syncronize file, directories, links for 2 nodes.
unison is ok, as long as your file/folders name don't use unicode, especially cross platform. Can't hurt to give it a try.
See Here for the limitation on unicode in filename.
What is the recommended way of having several cabal packages in one directory?
Why: I have an old project with many separable modules. Since originally they formed just one program it was, and still is, handy to have them in same directory for easy compiling.
Options
Just suffer and split everything, including VCS holding the stuff, into different directories?
Hack cabal until it is happy with multiple .cabal files in same directory?
Make another subdirectory for each module and put .cabal files there along with symlinks to original pieces of code?
Something smarter? What?
I'd have to recommend option 1 or 3 for cleanliness. I'm not sure how to get around this, if there is even a way to get around this.
I'd say a modified option of 1: subdirectories for everything, no symlinks, but keep everything under a single VCS.
This problem is on the issue list for Cabal 2.
I would recommend that this is exactly what workspaces in Leksah were designed to do. Just get your hands on Leksah and then the rest will sort itself out.