Hi Jimi, Since I have more or less the same problem, I did like this:
1. Set to use the ubuntu repo in your APT: deb https://qgis.org/ubuntu bionic main deb-src https://qgis.org/ubuntu bionic main 2. Try to install QGIS or any packages that you need. 3. If you get the `The following packages have unmet dependencies.` problem, just remove the package. For example in your case `libgdal20` (sudo apt remove libgdal20). 4. If the package is not found, try to find the package name, for example by using `dpkg -l | grep gdal`. Remove the packages. 5. Try again to install your package (from step 2), see if the problem persists. In my case, I got this The following packages have unmet dependencies when I want to install QGIS, then QGIS requirement for building from source. I got missing saga-common, gdalabi, and libopencv-calib3d3.2. I did the steps above, and now it works fine. Basically, what I understand is, there is a problem in the package, so remove it, and the package manager will re-install it while you are installing QGIS. CMIIW. I hope it helps. Best regards. On Thu, Feb 27, 2020 at 11:58 PM J. M <jimimc...@gmail.com> wrote: > Hi there guys, > > I think I've done everything that people have suggested, including Andre's > last suggestion: > sudo apt-get install libgdal20=2.2.3+dfsg-2, which returned this, similar > to last time: > > sudo apt-get install libgdal20=2.2.3+dfsg-2 > Reading package lists... Done > Building dependency tree > Reading state information... Done > Some packages could not be installed. This may mean that you have > requested an impossible situation or if you are using the unstable > distribution that some required packages have not yet been created > or been moved out of Incoming. > The following information may help to resolve the situation: > > The following packages have unmet dependencies. > libgdal20 : Depends: libogdi3.2 (>= 3.2.0) but it is not going to be > installed > E: Unable to correct problems, you have held broken packages. > > As I can't get beyond that point I have no idea what else to try, to be > honest. As Ben suggested I edited the etc file to include this: > deb https://qgis.org/ubuntu-ltr bionic main, because Ubuntu 18.04 LTS > doesn't yet support QGIS 3.12. If you can install QGIS and run it, then how > do you simply remove the entire program and all its dependencies so that > you can start from scratch? If I run purge X on any other program I think > my system removes it completely, though I'm not sure. > > Fernando Moxo suggested the following, but I've already run sudo apt-get > autoremove qgis (as QGIS wasn't the last program I installed and I don't > want this process to randomly erase vital dependencies and leave me with > half an OS) and there are fewer unmet dependencies now than the first time, > but I don't know what 'installed prereq.' means, or 'Id those prereq'. > Sorry, I can't act on that line because I don't understand it. > > sudo apt autoremove > > Should uninstall all dangling installed prereq. Id those prereq are > being kept due to some other package requiring them, or some remaining > from previous Qgis install it can take a bit more effort to fix. > > > I don't know how to erase individual dependencies, so without specific > commands I wouldn't know where to start. I ran autoremove and I thought it > took out everything, even dependencies unrelated to QGIS. Out of curiosity, > are the majority of QGIS users software developers as well? I've never > experienced this level of technical difficulty associated with the > installation of a piece of software on Linux before (I've been a dedicated > Ubuntu user since 12.04 LTS). > > Could someone recommend where to start from scratch, and suggest what to > do step-by-step, so I'm not cluttering up the group email with the same > queries for ages? I had it working perfectly (albeit briefly) before I > accidentally installed the ubuntugis-unstable PPA, so I know it's not a > problem with my OS. > Many thanks again, > Jimi. > > > > On Thu, Feb 27, 2020 at 1:10 PM Fernando M. Roxo da Motta <pe...@roxo.org> > wrote: > >> On Wed, 26 Feb 2020 12:33:24 +0800, Ben Hur Pintor <bnhr....@gmail.com> >> wrote: >> >> >> > Hi! >> > >> > It looks like your machine is trying to install 3.12. >> >> This kind of error usually indicates that 3.12 is already >> installed. Prossibly a previous install brought in the 3.12 version as >> a pre-requirement. If that is so, a command like: >> >> $ sudo apt autoremove >> >> Should uninstall all dangling installed prereq. Id those prereq are >> being kept due to some other package requiring them, or some remaining >> from previous Qgis install it can take a bit more effort to fix. >> >> Try to remove directly each of those dependencies. >> >> >> HTH >> >> > >> > As I mentioned in the last part of my previous message, right now you >> > can't install QGIS 3.12 on Ubuntu 18.04 because 3.12 needs PROJ 6.3.1 >> > which currently isn't available in Bionic -- via the main canonical >> > repo or even with the ubuntugis-unstable PPA. Therefore, I suggest >> > installing from the LTR branch and not the LR branch. When I use the >> > LTR branch with ubuntugis dependencies, I get QGIS 3 10.2 no problem. >> > >> > I run the same machine as you and actually faced the same problem >> > when I tried to install the Latest Release (3.12) on Bionic. Try >> > using the repos for the LTR (the ones with -ltr in the end). Maybe >> > that will help. >> > >> > Don't worry about it, we've all been there. >> > >> > >> > All the best, >> > Ben Hur >> > >> > On Wed, Feb 26, 2020, 07:12 J. M <jimimc...@gmail.com> wrote: >> > >> > > Hi Ben, >> > > >> > > No joy, I'm afraid. I think I did everything you recommended. I'm >> > > going to run through it in case I missed something obvious: >> > > >> > > - I ran sudo apt remove qgis grass qgis-plugin-grass, then ran >> > > sudo apt-get update >> > > - The /etc/apt/sources file contains the correct info because I >> > > modified it for the last installation >> > > - I ran autoremove on QGIS and erased over a gigabyte of >> > > dependencies (which seemed like a *lot*..) >> > > - I ran sudo apt-key list to check if the ubuntugis-unstable PPA >> > > was still listed as trusted, and it didn't appear >> > > - I added the ubuntugis stable PPA as recommended on >> > > https://trac.osgeo.org/ubuntugis/wiki/UbuntuGISRepository, with >> > > sudo add-apt-repository ppa:ubuntugis/ppa, and it appeared to >> > > duplicate your command sudo apt-key adv --keyserver >> > > keyserver.ubuntu.com --recv-key 51F523511C7028C3. Is that possible >> > > when they appear to reference two different PPA's? >> > > - I ran sudo apt-get install qgis qgis-plugin-grass and received >> > > the following error message, similar to before: >> > > >> > > The following packages have unmet dependencies. >> > > qgis : Depends: gdal-abi-2-2-3 >> > > Depends: libqgis-analysis3.12.0 but it is not going to be >> > > installed Depends: libqgis-app3.12.0 but it is not going to be >> > > installed Depends: libqgis-core3.12.0 but it is not going to be >> > > installed Depends: libqgis-gui3.12.0 but it is not going to be >> > > installed Depends: python3-qgis (= 1:3.12.0+28bionic) but it is not >> > > going to be installed >> > > Depends: qgis-providers (= 1:3.12.0+28bionic) but it is not >> > > going to be installed >> > > qgis-plugin-grass : Depends: qgis-provider-grass (= >> > > 1:3.12.0+28bionic) but it is not going to be installed >> > > Depends: grass740 >> > > Depends: libqgis-app3.12.0 but it is not going >> > > to be installed >> > > Depends: libqgis-core3.12.0 but it is not >> > > going to be installed >> > > Depends: libqgis-gui3.12.0 but it is not going >> > > to be installed >> > > Depends: libqgisgrass7-3.12.0 but it is not >> > > going to be installed >> > > E: Unable to correct problems, you have held broken packages. >> > > >> > > I must be missing something. Do I have to open the UI via terminal >> > > (sudo nautilus) and manually remove every file which makes >> > > reference to QGIS and ubuntugis-unstable? As formatting my machine >> > > isn't an option there must be a simple way of completely removing >> > > the program and its dependencies.. right?! >> > > >> > > I don't even know what Gdal is or does, because I can't even get >> > > started learning QGIS because I'm finding it impossible to have a >> > > version running for long enough to start with tutorials! Is it to >> > > allow you to overlay raster info onto GIS projects or something? I >> > > googled it but the explanation must have been written by a robot >> > > (no offence intended, to robots I mean). Gdal was the reason I >> > > installed the ubuntugis-unstable PPA, because Blender gave me the >> > > helpful error message: Please install gdal to enable raster >> > > projection support. As my crystal ball was clouded up when I read >> > > that I came here to bug you guys for help! >> > > >> > > >> > > Thanks again to everyone who has had a go at helping me. Keep those >> > > ideas coming!! >> > > Cheers, >> > > Jimi. >> > > >> > > On Tue, Feb 25, 2020 at 11:39 PM J. M <jimimc...@gmail.com> wrote: >> > > >> > >> Hi Ben! >> > >> >> > >> Thanks a lot for that, really helpful; I'll give it a go. It was >> > >> actually the ubuntugis unstable PPA which caused the current >> > >> problem I'm having, so I'm keen to avoid that PPA if I can. I'll >> > >> try your steps again and let you know what the outcome is. >> > >> >> > >> Cheers, >> > >> Jimi. >> > >> >> > >> On Tue, Feb 25, 2020 at 4:44 AM Ben Hur Pintor <bnhr....@gmail.com> >> > >> wrote: >> > >> >> > >>> Hi! >> > >>> >> > >>> First of all, make sure that you add the qgis.org repo public key >> > >>> via sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-key >> > >>> 51F523511C7028C3. Make sure that the library versions in your >> > >>> computer (specially GDAL and PROJ) are the same libraries that >> > >>> QGIS is built against. >> > >>> >> > >>> The links in >> > >>> >> https://www.qgis.org/en/site/forusers/alldownloads.html#debian-ubuntu >> > >>> determine which versions of QGIS will be installed. You add these >> > >>> as sources in the Software Center or you can add them directly in >> > >>> your /etc/apt/sources.list file as instructed in >> > >>> https://qgis.org/en/site/forusers/alldownloads.html#debian-ubuntu. >> > >>> If you want 3.12 (Latest Release), you can use/add the following >> > >>> in your /etc/apt/sources.list file https://qgis.org/ubuntu or >> > >>> https://qgis.org/ubuntugis (if with ubuntugis-unstable >> > >>> dependencies). If you want the LTR branch (3.10.3), simply use >> > >>> https://qgis.org/ubuntu-ltr or https://qgis.org/ubuntugis-ltr (if >> > >>> with ubuntugis-unstable dependencies) in >> > >>> your /etc/apt/sources.list file. >> > >>> >> > >>> Also, don't forget to remove/purge all previous QGIS or GRASS >> > >>> installations (e.g. sudo apt remove qgis grass qgis-plugin-grass) >> > >>> and do an update (sudo apt update) before trying to install QGIS >> > >>> again. >> > >>> >> > >>> I run Pop! OS 18.04 (based on Ubuntu 18.04). Unfortunately, the >> > >>> libraries in the main (universe) repo of Bionic are a bit >> > >>> outdated (GDAL 2.2.3, PROJ 4.9, etc.). The newer versions of QGIS >> > >>> use GDAL 3.0.X and PROJ 6.X. Using the ubuntugis-unstable ( >> > >>> https://launchpad.net/~ubuntugis/+archive/ubuntu/ubuntugis-unstable >> ) >> > >>> PPA remedies the problem of some outdated libraries. If you will >> > >>> use the ubuntugis-unstable libraries, don't forget to add the PPA >> > >>> to your sources as well. On another note, PROJ 6.3.1, which QGIS >> > >>> 3.10.3 and 3.12 use, isn't available yet in Bionic even when >> > >>> using the ubuntugis PPA so even if I want, I can only install >> > >>> 3.10.2 right now on my machine. Trying to install 3.12 via the >> > >>> ubuntu or ubuntugis repo fails. >> > >>> >> > >>> >> > >>> All the best, >> > >>> Ben Hur >> > >>> >> > >>> On Tue, Feb 25, 2020, 07:25 J. M <jimimc...@gmail.com> wrote: >> > >>> >> > >>>> Hi Ismail, >> > >>>> >> > >>>> Well, I've tried everything I can think of, everything people >> > >>>> have recommended and everything I've googled, but there seems to >> > >>>> be no earthly way to get rid of the following error messages: >> > >>>> >> > >>>> sudo apt-get install qgis qgis-plugin-grass >> > >>>> Reading package lists... Done >> > >>>> Building dependency tree >> > >>>> Reading state information... Done >> > >>>> Some packages could not be installed. This may mean that you have >> > >>>> requested an impossible situation or if you are using the >> > >>>> unstable distribution that some required packages have not yet >> > >>>> been created or been moved out of Incoming. >> > >>>> The following information may help to resolve the situation: >> > >>>> >> > >>>> The following packages have unmet dependencies. >> > >>>> qgis : Depends: python3-qgis (= 1:3.12.0+28bionic) but it is >> > >>>> not going to be installed >> > >>>> E: Unable to correct problems, you have held broken packages. >> > >>>> >> > >>>> I've tried this: >> > >>>> >> > >>>> sudo apt-get purge qgis >> > >>>> sudo apt-get autoremove qgis >> > >>>> sudo apt-get --purge remove qgis >> > >>>> sudo apt-get update >> > >>>> >> > >>>> but it returned the following: >> > >>>> >> > >>>> sudo apt-get update >> > >>>> >> > >>>> >> > >>>> Hit:6 http://qgis.org/debian bionic InRelease >> > >>>> >> > >>>> The following signatures couldn't be verified because the >> > >>>> public key is not available: NO_PUBKEY 76F1A20FF987672F >> > >>>> Hit:18 >> > >>>> http://ppa.launchpad.net/ubuntugis/ubuntugis-unstable/ubuntu >> > >>>> bionic InRelease Err:18 >> > >>>> http://ppa.launchpad.net/ubuntugis/ubuntugis-unstable/ubuntu >> > >>>> bionic InRelease The following signatures couldn't be verified >> > >>>> because the public key is not available: NO_PUBKEY >> > >>>> 089EBE08314DF160 Reading package lists... Done >> > >>>> W: GPG error: https://dl.winehq.org/wine-builds/ubuntu bionic >> > >>>> InRelease: The following signatures couldn't be verified because >> > >>>> the public key is not available: NO_PUBKEY 76F1A20FF987672F >> > >>>> E: The repository 'https://dl.winehq.org/wine-builds/ubuntu >> > >>>> bionic InRelease' is not signed. >> > >>>> N: Updating from such a repository can't be done securely, and is >> > >>>> therefore disabled by default. >> > >>>> N: See apt-secure(8) manpage for repository creation and user >> > >>>> configuration details. >> > >>>> W: An error occurred during the signature verification. The >> > >>>> repository is not updated and the previous index files will be >> > >>>> used. GPG error: >> > >>>> http://ppa.launchpad.net/ubuntugis/ubuntugis-unstable/ubuntu >> > >>>> bionic InRelease: The following signatures couldn't be verified >> > >>>> because the public key is not available: NO_PUBKEY >> > >>>> 089EBE08314DF160 >> > >>>> >> > >>>> >> > >>>> I can't think of anything else. Any suggestions about what I >> > >>>> might be doing wrong? I don't actually understand what this link >> > >>>> is for: >> > >>>> >> https://www.qgis.org/en/site/forusers/alldownloads.html#debian-ubuntu >> > >>>> If you download via the terminal by typing 'sudo apt-get install >> > >>>> qgis' then how do you make use of all the folders in this link? >> > >>>> I mean, how do I differentiate if I want to download version >> > >>>> 3.10 or 3.12 of QGIS? >> > >>>> >> > >>>> Sorry team, I just can't get this to work and I'm worried I do >> > >>>> irreparable damage to my system with this process. >> > >>>> Please help me out, guys! >> > >>>> Cheers, >> > >>>> Jimi. >> > >>>> >> > >>>> >> > >>>> >> > >>>> On Mon, Feb 24, 2020 at 6:58 PM J. M <jimimc...@gmail.com> wrote: >> > >>>> >> > >>>>> Hi Ismail! >> > >>>>> >> > >>>>> Many thanks for your advice; I'll check it out. I haven't >> > >>>>> actually had a chance to sit down and try to purge QGIS and >> > >>>>> start again. Andre was trying to help me but I wasn't sure >> > >>>>> where to start so I haven't tried since I last inquired about >> > >>>>> the process! >> > >>>>> >> > >>>>> Thanks a lot, >> > >>>>> Jimi. >> > >>>>> >> > >>>>> On Sun, Feb 23, 2020 at 8:59 AM Ismail Sunni >> > >>>>> <imajimat...@gmail.com> wrote: >> > >>>>> >> > >>>>>> Hi Jimi, >> > >>>>>> >> > >>>>>> I have a similar problem. I fix it by reinstalling gdal >> > >>>>>> (libgdal20). I can install QGIS again after that. But, I am >> > >>>>>> not an expert with this package manager thing, so perhaps it >> > >>>>>> can work for you also, or perhaps not :) >> > >>>>>> >> > >>>>>> While trying to fix my problem, I found this >> > >>>>>> >> https://askubuntu.com/questions/140246/how-do-i-resolve-unmet-dependencies-after-adding-a-ppa >> > >>>>>> which probably useful for you. >> > >>>>>> >> > >>>>>> Best regards >> > >>>>>> >> > >>>>>> On Thu, Feb 20, 2020 at 1:22 PM J. M <jimimc...@gmail.com> >> > >>>>>> wrote: >> > >>>>>>> Hi again Andre, >> > >>>>>>> >> > >>>>>>> Thanks for that, I more or less get what you mean. The >> > >>>>>>> problem is that when I ran autoremove it came back with >> > >>>>>>> almost a gig of dependencies it wanted to remove, so I >> > >>>>>>> cancelled it! QGIS wasn't the last program I installed so I >> > >>>>>>> have no idea how to purge only the dependencies directly >> > >>>>>>> related to the previous version of it I was running. If I run >> > >>>>>>> autoremove and it damages other applications or makes my >> > >>>>>>> system unusable then I won't be able to fix it (I'm only a >> > >>>>>>> user, I've got no background in programming). I read around >> > >>>>>>> and people warned strongly against doing this unless you're >> > >>>>>>> sure what you want to remove. How can I be sure I only remove >> > >>>>>>> the right dependencies? Does QGIS have a list or something I >> > >>>>>>> can use as a guide? >> > >>>>>>> >> > >>>>>>> If anyone could explain how to use Synaptic package manager >> > >>>>>>> then I'd be really grateful! It must have the most >> > >>>>>>> unintuitive interface of any piece of software I've ever >> > >>>>>>> tried to use.. >> > >>>>>>> >> > >>>>>>> I edited the source file last time I installed it, so that >> > >>>>>>> part is done. Incidentally, I don't see the 'other Software' >> > >>>>>>> tab in the Ubuntu Software Center, so I just edited it >> > >>>>>>> manually. Any idea what that package is called? I'm happy >> > >>>>>>> enough using the terminal if I know (roughly) what I'm doing! >> > >>>>>>> >> > >>>>>>> Thanks a lot team, >> > >>>>>>> Jimi. >> > >>>>>>> >> > >>>>>>> On Wed, Feb 19, 2020 at 8:18 PM Andre Joost < >> > >>>>>>> andre+jo...@nurfuerspam.de> wrote: >> > >>>>>>> >> > >>>>>>>> Am 18.02.20 um 23:58 schrieb J. M: >> > >>>>>>>> > Hi again Andre, >> > >>>>>>>> > >> > >>>>>>>> > I don't actually understand what to do with this, because >> > >>>>>>>> > I can't >> > >>>>>>>> run 'sudo >> > >>>>>>>> > apt-get install qgis qgis-plugin-grass' as it keeps giving >> > >>>>>>>> > me the >> > >>>>>>>> same >> > >>>>>>>> > error messages about broken packages. >> > >>>>>>>> >> > >>>>>>>> Yes, because you have packages that are compiled against a >> > >>>>>>>> set of libraries that does not match your computer. You have >> > >>>>>>>> to remove, autoremove and purge those QGIS packages to force >> > >>>>>>>> a download from the >> > >>>>>>>> right folder. >> > >>>>>>>> >> > >>>>>>>> >> > >>>>>>>> > When you say this, I don't get what this link does. I >> > >>>>>>>> > click on it >> > >>>>>>>> and it >> > >>>>>>>> > just takes me into a file hierarchy. Are users supposed to >> > >>>>>>>> > obtain >> > >>>>>>>> the >> > >>>>>>>> > downloads from here, or is it purely informative? >> > >>>>>>>> > Try >> > >>>>>>>> > deb https://qgis.org/ubuntugis bionic main >> > >>>>>>>> >> > >>>>>>>> That should go into your sources list, to replace the QGIS >> > >>>>>>>> download source you used before. The Ubuntu Software center >> > >>>>>>>> has a tab for "other >> > >>>>>>>> Software" that holds the same information, so no need to >> > >>>>>>>> edit the sources file manually. >> > >>>>>>>> >> > >>>>>>>> HTH, >> > >>>>>>>> Andre Joost >> > >>>>>>>> >> > >>>>>>>> >> > >>>>>>>> _______________________________________________ >> > >>>>>>>> Qgis-user mailing list >> > >>>>>>>> Qgis-user@lists.osgeo.org >> > >>>>>>>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user >> > >>>>>>>> Unsubscribe: >> > >>>>>>>> https://lists.osgeo.org/mailman/listinfo/qgis-user >> > >>>>>>> >> > >>>>>>> _______________________________________________ >> > >>>>>>> Qgis-user mailing list >> > >>>>>>> Qgis-user@lists.osgeo.org >> > >>>>>>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user >> > >>>>>>> Unsubscribe: >> > >>>>>>> https://lists.osgeo.org/mailman/listinfo/qgis-user >> > >>>>>> >> > >>>>>> >> > >>>>>> >> > >>>>>> -- >> > >>>>>> Ismail Sunni >> > >>>>>> Software Engineer >> > >>>>>> ismailsunni.id >> > >>>>>> ismailsunni.wordpress.com >> > >>>>>> >> > >>>>> _______________________________________________ >> > >>>> Qgis-user mailing list >> > >>>> Qgis-user@lists.osgeo.org >> > >>>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user >> > >>>> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user >> > >>> >> > >>> >> >> >> >> >> >> >> >> >> Roxo >> >> -- >> ---------------- Non luctari, ludare -------------------+ WYSIWYG >> Fernando M. Roxo da Motta <pe...@roxo.org> | Editor? >> Except where explicitly stated I speak on my own behalf.| VI !! >> PU5RXO | I see text, >> ------------ Quis custodiet ipsos custodes?-------------+ I get text! >> >> _______________________________________________ >> Qgis-user mailing list >> Qgis-user@lists.osgeo.org >> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user >> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user > > _______________________________________________ > Qgis-user mailing list > Qgis-user@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user -- Ismail Sunni Software Engineer ismailsunni.id ismailsunni.wordpress.com
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