[Pharo-users] uFFI: Debugging "External module not found" Error
I was trying to get Pharo-LibVLC working on Mac. The following is copied from a GH issue[1]: > I have VLC installed via Homebrew cask, the formula for which simply > installs the dmg. I > first tried supplying a full path to the dylib that the VLC app uses > (/Applications/VLC.app/Contents/MacOS/lib/libvlc.5.dylib), which resulted > in "Error: > External module not found". I then remembered some trouble people have had > in the past > with FFI lookup locations and tried copying into the VM's plugin folder > both a link and the > actual dylib, with the same error. I read the uFFI booklet, but didn't > learn anything more. > > I also checked that the VLC lib was 64-bit via: > > lipo -info .../Pharo.app/Contents/MacOS/Plugins/libvlc.5.dylib > which returned: > Non-fat file: .../Plugins/libvlc.5.dylib is architecture: x86_64 [1] https://github.com/badetitou/Pharo-LibVLC/issues/1 - Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html
Re: [Pharo-users] uFFI: Debugging "External module not found" Error
On Wed, 4 Dec 2019 at 00:26, Sean P. DeNigris wrote: > I was trying to get Pharo-LibVLC working on Mac. The following is copied > from > a GH issue[1]: > > > I have VLC installed via Homebrew cask, the formula for which simply > > installs the dmg. I > > first tried supplying a full path to the dylib that the VLC app uses > > (/Applications/VLC.app/Contents/MacOS/lib/libvlc.5.dylib), which resulted > > in "Error: > > External module not found". I then remembered some trouble people have > had > > in the past > > with FFI lookup locations and tried copying into the VM's plugin folder > One catch that has confused me in the past, is when the system caches that it couldn't find the external module, so even when I copyied it to the VM folder or got the path correct, it continued to fail until I restarted the Image. cheers -ben > > both a link and the > > actual dylib, with the same error. I read the uFFI booklet, but didn't > > learn anything more. > > > > I also checked that the VLC lib was 64-bit via: > > > > lipo -info .../Pharo.app/Contents/MacOS/Plugins/libvlc.5.dylib > > which returned: > > Non-fat file: .../Plugins/libvlc.5.dylib is architecture: x86_64 > > [1] https://github.com/badetitou/Pharo-LibVLC/issues/1 > > > > - > Cheers, > Sean > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html > >
Re: [Pharo-users] uFFI: Debugging "External module not found" Error
Ben Coman wrote > One catch that has confused me in the past, is when the system caches that > it couldn't find the external module, > so even when I copyied it to the VM folder or got the path correct, it > continued to fail until I restarted the Image. Great gotcha! We should add that to the docs. I'll have a go after I figure this error out. In my case, restarting did not help :/ - Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html
Re: [Pharo-users] uFFI: Debugging "External module not found" Error
Hi Sean, On Tue, 3 Dec 2019 at 17:26, Sean P. DeNigris wrote: > > I was trying to get Pharo-LibVLC working on Mac. The following is copied from > a GH issue[1]: > > > I have VLC installed via Homebrew cask, the formula for which simply > > installs the dmg. I > > first tried supplying a full path to the dylib that the VLC app uses > > (/Applications/VLC.app/Contents/MacOS/lib/libvlc.5.dylib), which resulted > > in "Error: > > External module not found". I then remembered some trouble people have had > > in the past > > with FFI lookup locations and tried copying into the VM's plugin folder > > both a link and the > > actual dylib, with the same error. I read the uFFI booklet, but didn't > > learn anything more. > > > > I also checked that the VLC lib was 64-bit via: > > > > lipo -info .../Pharo.app/Contents/MacOS/Plugins/libvlc.5.dylib > > which returned: > > Non-fat file: .../Plugins/libvlc.5.dylib is architecture: x86_64 The same message is returned whether the module itself isn't found, or if one of its dependencies can't be found. On linux you can check dependencies with `ldd file.so`, I don't know what the Mac equivalent is. HTH, Alistair
Re: [Pharo-users] [vwnc] Parsing in Smalltalk
Steffen Märcker wrote > I can send you that code. Awesome. I'll email you. Although, I wonder how relevant this is given your answers down below. Are there many grammars available in Xtreams syntax to make this useful? Also, what is the license? Can I add it somewhere on GH under MIT (with attribution of course)? Steffen Märcker wrote > However, I moved away from Xtreams own PEG flavor to Bryan Ford's > original PEG syntax (close but more common) Ah, interesting. I didn't realize that Xtreams used a custom PEG syntax. I wonder why?! Steffen Märcker wrote > From Bryan Ford's original PEG syntax: > 1. Xtreams Grammer and Actor that build an Xtreams parser > ... > All three are available for VW in the Cincom's public repository: > - Xtreasm-Parsing (8.2-3,stm): +PEG parser +some fixes to Xtreams parser I'd certainly like to port that at some point, but I'm currently fairly mystified about the best practice process. I just reached out to Pavel about the Ring2 approach on which he spoke at ESUG. Do you have a documented process or any pointers even? Steffen Märcker wrote > And 2, 3 for Pharo on GitHub, e.g. > - https://github.com/kursjan/petitparser2/tree/master/PetitParser2-PEG Great. I use PP2 a lot. So if IIUC, I can now feed a PEG-syntax grammar string and have a PP2 parser generated for it? Steffen Märcker wrote > Speaking of, I just noticed that translator form Xtreams.PEG to PEG is > missing to complete the picture here. ;-) Ah, yes that makes sense. Any idea how much effort would be involved? Steffen Märcker wrote > As far as I know, there is no BNF-like parser generator for Xtreams, > available. > ... > Is it an option for you to convert your BNF to PEG manually? I'm not a parsing expert, so that may have been what I'm already doing and I'm using the wrong terminology. I took the ABNF from rfc5322 [1] and adapted it slightly [2] to be consumed by Xtreams [3] [OT?] As a final aside, I've been wondering if there's any way to generate "hand-rolled" equivalent parsers from Xtreams, PP, etc. for use cases where none of the libraries are available. I have in mind Pharo's MailMessage. It doesn't seem like any full-featured parsing libraries will be integrated any time soon, so the lowest levels use painful, duplication-riddled hand-rolled parsers. It would be great to leverage all this great library tech to create and reason about those... [/OT] Thanks for the discussion! 1. https://tools.ietf.org/html/rfc5322 2. https://github.com/seandenigris/Xtreams-Pharo/blob/master/repository/Xtreams-Email.package/PEGParser.extension/class/grammarEmail.st 3. https://github.com/seandenigris/Xtreams-Pharo/blob/master/repository/Xtreams-Email.package/PEGParserEmailTest.class/instance/setUp.st - Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html
Re: [Pharo-users] uFFI: Debugging "External module not found" Error
Alistair Grant wrote > The same message is returned whether the module itself isn't found, or > if one of its dependencies can't be found. Good to know. I wonder if we can't provide more detailed error messages here... Alistair Grant wrote > On linux you can check dependencies with `ldd file.so`, I don't know > what the Mac equivalent is. Apparently, it's `otool -L whatever.dylib`, which returns: @rpath/libvlc.dylib (compatibility version 12.0.0, current version 12.0.0) @rpath/libvlccore.dylib (compatibility version 10.0.0, current version 10.0.0) /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1252.50.4) /usr/lib/libiconv.2.dylib (compatibility version 7.0.0, current version 7.0.0) Still investigating... - Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html
Re: [Pharo-users] uFFI: Debugging "External module not found" Error
--- Begin Message --- This is the most annoying thing about UFFI - the library search seems to opaque and I don't understand how it works. So far I am finding best practice is to find the library yourself and then provide the exact file path you want. That way, you can actually prompt the user to find it if you don't and they get a decent experience. > On Dec 3, 2019, at 11:34 AM, Sean P. DeNigris wrote: > > Alistair Grant wrote >> The same message is returned whether the module itself isn't found, or >> if one of its dependencies can't be found. > > Good to know. I wonder if we can't provide more detailed error messages > here... > > > Alistair Grant wrote >> On linux you can check dependencies with `ldd file.so`, I don't know >> what the Mac equivalent is. > > Apparently, it's `otool -L whatever.dylib`, which returns: > @rpath/libvlc.dylib (compatibility version 12.0.0, current version > 12.0.0) > @rpath/libvlccore.dylib (compatibility version 10.0.0, current version > 10.0.0) > /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version > 1252.50.4) > /usr/lib/libiconv.2.dylib (compatibility version 7.0.0, current version > 7.0.0) > > > Still investigating... > > > > - > Cheers, > Sean > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html > --- End Message ---
Re: [Pharo-users] uFFI: Debugging "External module not found" Error
> > > On Dec 3, 2019, at 11:34 AM, Sean P. DeNigris > wrote: > > > > Alistair Grant wrote > >> The same message is returned whether the module itself isn't found, or > >> if one of its dependencies can't be found. > Secondary dependencies are awkward to track via command line. > > > > Good to know. I wonder if we can't provide more detailed error messages > > here... > The following turned up in a search (I've no experience with it), but could be useful... https://linux.die.net/man/7/rtld-audit Or perhaps the system can examine the DYNAMIC section of an ELF to pre-load each dependency. >From the image, something in part equivalent to... https://github.com/finixbit/elf-parser/blob/master/elf_parser.cpp GT inspector on an ELF file could an interesting demo ;) btw, I wasn't aware of how "Runtime Search Path: Security" affected the search path... https://amir.rachum.com/blog/2016/09/17/shared-libraries/ > Alistair Grant wrote > >> On linux you can check dependencies with `ldd file.so`, I don't know > >> what the Mac equivalent is. > > > > Apparently, it's `otool -L whatever.dylib`, which returns: > > @rpath/libvlc.dylib (compatibility version 12.0.0, current version > 12.0.0) > > @rpath/libvlccore.dylib (compatibility version 10.0.0, current > version > > 10.0.0) > > /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current > version > > 1252.50.4) > > /usr/lib/libiconv.2.dylib (compatibility version 7.0.0, current > version > > 7.0.0) > On Wed, 4 Dec 2019 at 03:58, Todd Blanchard via Pharo-users < pharo-users@lists.pharo.org> wrote: > This is the most annoying thing about UFFI - the library search seems to > opaque and I don't understand how it works. > > So far I am finding best practice is to find the library yourself and then > provide the exact file path you want. > > That way, you can actually prompt the user to find it if you don't and > they get a decent experience. > cheers -ben P.S. an interesting side article... https://medium.com/forensicitguy/whitelisting-ld-preload-for-fun-and-no-profit-98dfea740b9
[Pharo-users] some sort of mentor help ?
--- Begin Message --- Hello, do not know if this is the right channel but is there someone or some book which can help me learn how to approach complex problems like the AdventOfCode challenges , I try that but im stuck because most of the time I have the feeling I choose a difficult solution where some easier one exist. or I have a very bad plan that is a wall I hit many times with my languages and I need a way to get out of it and make a step further with Pharo Regards, Roelof --- End Message ---
Re: [Pharo-users] some sort of mentor help ?
--- Begin Message --- I looked at the site and I knocked out day 1. These are little programming puzzles you can do in a playground. Day 1's first puzzles is literally a 1 liner. The story telling obfuscates the problem and can make the problem seem harder than it is. You have to learn to cut through the noise and see the problem. You are supposed to find the amount of fuel required to launch a given mass into space in a rocket. This is the key paragraph. "Fuel required to launch a given module is based on its mass. Specifically, to find the fuel required for a module, take its mass, divide by three, round down, and subtract 2." The code for this is: fuel := (mass / 3) floor - 2. The floor function rounds downwards. To round up you use ceiling. You have a list of modules though. If you click to get your module mass list, its a page with one number per line. Getting this into a collection is really easy. masses := #( ) and execute that in your playground. This is your input data. To get the fuel for each mass, a collect: seems like a winner. fuels := masses collect: [:mass | (mass / 3) floor - 2 ]. The final thing he wants is the total amount of fuel required. You just add up the numbers. total := fuels sum. I leave the second puzzle of day 1 to you, it is almost the same except you have to iteratively calculate the fuel to lift the fuel you add. To do this you end up putting a loop into the collect; block and executing it over and over until the amount of additional fuel is <= zero. I hope this gets you going. You can email me directly at tblanch...@mac.com if you get stuck. > On Dec 3, 2019, at 2:54 PM, Roelof Wobben via Pharo-users > wrote: > > > From: Roelof Wobben > Subject: some sort of mentor help ? > Date: December 3, 2019 at 2:54:19 PM PST > To: pharo-users@lists.pharo.org > > > Hello, > > do not know if this is the right channel but is there someone or some book > which can help me learn how to approach complex problems like the > AdventOfCode challenges , I try that but im stuck because most of the time I > have the feeling I choose a difficult solution where some easier one exist. > or I have a very bad plan > that is a wall I hit many times with my languages and I need a way to get out > of it and make a step further with Pharo > > Regards, > > Roelof > > > --- End Message ---
