Compiling cpython code on Ubuntu 16.04

Question

I was the following the instructions on the official cpython code link here. I did a

hg update 3.5

and then did the following.

sudo apt-get build-dep python3.5

But it is throwing up an error stating the statements listed below:

Reading package lists... Done
Picking 'python3-defaults' as source package instead of 'python3'
E: Unable to find a source package for python3

I did read about reducing the version and trying the above set of code, which also conked for the following reason.

$ hg update 2.7
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ sudo apt-get build-dep python2.7
Reading package lists... Done
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:
builddeps:python2.7 : Depends: libdb5.1-dev but it is not installable
E: Unable to correct problems, you have held broken packages

To resolve the above error, I did the following which also threw up an error.

$ sudo apt-get install libdb5.1-dev
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package libdb5.1-dev is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or is only available from another source

E: Package 'libdb5.1-dev' has no installation candidate

To resolve that error, I tried doing the following.

$ sudo apt-get install libdb5.1++-dev
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package libdb5.1++-dev is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or is only available from another source

E: Package 'libdb5.1++-dev' has no installation candidate

Finally I did do this.

sudo apt-get install libdb++-dev

It was already installed and but the build-dep does not point towards it and still throws up an error.

I am not sure what is going wrong? Can someone help?

Thanks in advance!

Answer 1

You did not say what version of libdb you do have. Libdb++ is only for programs that will use the C++ interface, which I do not think you need. I see libdb version 5.3.21 and libdb4 version 4.8.30. If you already have version 5.3.21, the dynamic libraries should be user /usr/lib64 as libdb-5.3.so and a link to that library libdb-5.so. (I am working on CentOS so it may be slightly different for Ubuntu.) You can create another link from libdb-5.1.so to the library you have, reinstall python3.5 and tell apt-get to ignore dependencies with the --no-deps option.