[Issue 18649] curl on Ubuntu 18.04 depends on libcurl4, .deb installer depends on libcurl3

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=18649

Seb <greensunny12 at gmail.com> changed:

           What    |Removed                     |Added
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                 CC|                            |greensunny12 at gmail.com

--- Comment #1 from Seb <greensunny12 at gmail.com> ---
I was shocked a bit about this because I thought libcurl4 doesn't exist in
Ubuntu and is currently only available in experimental in Debian:

https://packages.debian.org/experimental/libcurl4
https://packages.ubuntu.com/search?keywords=libcurl&searchon=names&suite=artful&section=all

The binary library is called libcurl3 (the API/development packages is
libcurl4-dev)

https://askubuntu.com/questions/469360/what-is-the-difference-between-libcurl3-and-libcurl4

However, I tried this myself in Docker and I can reproduce this:

---
root at 84fd31deb36c:/# apt-get install libcurl3            
Reading package lists... Done
Building dependency tree       
Reading state information... Done
You might want to run 'apt --fix-broken install' to correct these.
The following packages have unmet dependencies:
 dmd : Depends: libc6-dev but it is not going to be installed
       Depends: gcc but it is not going to be installed
 libcurl3 : Depends: libssl1.0.0 (>= 1.0.2~beta3) but it is not going to be
installed
            Conflicts: libcurl4 but 7.58.0-2ubuntu3 is to be installed
 libcurl4 : Conflicts: libcurl3 but 7.58.0-2ubuntu2 is to be installed
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or
specify a solution).
---

---
root at 84fd31deb36c:/# apt-get install libcurl4
Reading package lists... Done
Building dependency tree       
Reading state information... Done
libcurl4 is already the newest version (7.58.0-2ubuntu3).
libcurl4 set to manually installed.
You might want to run 'apt --fix-broken install' to correct these.
The following packages have unmet dependencies:
 dmd : Depends: libc6-dev but it is not going to be installed
       Depends: gcc but it is not going to be installed
       Depends: libcurl3 but it is not going to be installed
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or
specify a solution).
---

At least it seems like dmd isn't the only application:
https://bugs.launchpad.net/ubuntu/+source/curl/+bug/1754294


BTW the file that creates the DEB ball is here:

https://github.com/dlang/installer/blob/master/linux/dmd_deb.sh#L347

I'm not sure what's the best fix for this as libcurl4 doesn't exist in Debian
(and the DEB ball is supposed to be general-purpose).

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