Jtdcftul

I can't fetch content from the web using curl. I tried to intall it the out put below.

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.
curl : Depends: libcurl4 (= 7.58.0-2ubuntu3) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

I've checked for held packages with both sudo apt-mark showheld & dpkg -l | grep ^h in hopes of getting a list of held packages but I get no results either way.

Also, when I attempt to install libcurl4 it almost going to break my system since it attempts to remove these packages below.

libcurl3 mongodb-enterprise mongodb-enterprise-server mongodb-enterprise-tools msodbcsql msodbcsql17 mssql-tools php7.1-curl r-base r-base-core
r-base-dev r-base-html r-cran-boot r-cran-class r-cran-codetools r-cran-foreign r-cran-getopt r-cran-kernsmooth r-cran-lattice r-cran-littler
r-cran-mass r-cran-matrix r-cran-mgcv r-cran-nlme r-cran-nnet r-cran-rpart r-cran-spatial r-cran-survival r-recommended slack-desktop
virtualbox-5.2

Edit

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to

# newer versions of the distribution. deb http://gb.archive.ubuntu.com/ubuntu/ bionic main restricted deb-src

http://gb.archive.ubuntu.com/ubuntu/ bionic main restricted



## Major bug fix updates produced after the final release of the

## distribution. deb http://gb.archive.ubuntu.com/ubuntu/ bionic-updates main restricted deb-src

http://gb.archive.ubuntu.com/ubuntu/ bionic-updates main restricted



## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu

## team. Also, please note that software in universe WILL NOT receive any

## review or updates from the Ubuntu security team. deb http://gb.archive.ubuntu.com/ubuntu/ bionic universe deb-src

http://gb.archive.ubuntu.com/ubuntu/ bionic universe



deb http://gb.archive.ubuntu.com/ubuntu/ bionic-updates universe

deb-src http://gb.archive.ubuntu.com/ubuntu/ bionic-updates universe



## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 

## team, and may not be under a free licence. Please satisfy yourself as to 

## your rights to use the software. Also, please note that software in 

## multiverse WILL NOT receive any review or updates from the Ubuntu

## security team. deb http://gb.archive.ubuntu.com/ubuntu/ bionic multiverse deb-src http://gb.archive.ubuntu.com/ubuntu/ bionic

multiverse



deb http://gb.archive.ubuntu.com/ubuntu/ bionic-updates multiverse

deb-src http://gb.archive.ubuntu.com/ubuntu/ bionic-updates multiverse



## N.B. software from this repository may not have been tested as

## extensively as that contained in the main release, although it includes

## newer versions of some applications which may provide useful features.

## Also, please note that software in backports WILL NOT receive any review

## or updates from the Ubuntu security team.

# deb-src http://gb.archive.ubuntu.com/ubuntu/ bionic-backports main restricted universe multiverse



## Uncomment the following two lines to add software from Canonical's

## 'partner' repository.

## This software is not part of Ubuntu, but is offered by Canonical and the

## respective vendors as a service to Ubuntu users. deb http://archive.canonical.com/ubuntu bionic partner deb-src

http://archive.canonical.com/ubuntu bionic partner



deb http://security.ubuntu.com/ubuntu bionic-security main restricted

deb-src http://security.ubuntu.com/ubuntu bionic-security main

restricted



deb http://security.ubuntu.com/ubuntu bionic-security universe deb-src

http://security.ubuntu.com/ubuntu bionic-security universe



deb http://security.ubuntu.com/ubuntu bionic-security multiverse

deb-src http://security.ubuntu.com/ubuntu bionic-security multiverse



deb http://gb.archive.ubuntu.com/ubuntu/ bionic-proposed main

multiverse universe restricted #Not for humans during development

stage of release bionic

# ded-src http://archive.ubuntu.com/ubuntu/ trusty-backports main restricted ui=niverse



deb http://gb.archive.ubuntu.com/ubuntu/ bionic-backports main

restricted multiverse universe

This problem is common in multiple packages in ubuntu recent LTS. Preinstalled packages have a possible error in version convention because "18.04" and other strings referencing repo are considering as part of the package version and not reference to the repo.

The workaround is uninstall preinstalled dependency and then reinstall. After that, you can install cURL.

apt remove -y libcurl4

apt install -y libcurl4 curl

Other packages with that problem are okular and libsdl2, and the solution is the same, track problematic dependencies, remove and reinstall.

Also, you can use apt downgrade mechanism (thus, is not necessary to uninstall packages that depend of libcurl4).

apt install -y libcurl4=7.58.0-2ubuntu3

apt install -y curl

Install curl from source . That worked for me

git clone https://github.com/curl/curl.git

https://curl.haxx.se/docs/install.html

./buildconf
./configure
make
make test (optional)
sudo make install

Try to use

sudo apt install libcurl4-openssl-dev

If necessary

sudo update

sudo apt remove libcurl4