Many Linux administrators encounter this puzzling behavior where deleting /usr/local/lib/libcurl.so.4 temporarily resolves the version warning, only for the symlink to magically reappear within 24-48 hours. Let's examine why this happens and how to properly fix it.

The core issue stems from having multiple curl installations conflicting with each other. Your system shows:

$ apt --installed list | grep 'curl'
curl/trusty-updates,trusty-security,now 7.35.0-1ubuntu2.5 amd64 [installed]
libcurl3/trusty-updates,trusty-security,now 7.35.0-1ubuntu2.5 amd64 [installed]

Meanwhile, you have a manually compiled version in /usr/local/lib with version 4.3.0, which lacks proper version information tags.

First, verify all curl installations on your system:

$ find /usr -name "*libcurl*" -ls
$ which -a curl
$ curl --version

The daily reappearance at 8:00:01 AM strongly suggests a cron job or system maintenance script is recreating the symlink. Common culprits include:

• Package maintainer scripts (/var/lib/dpkg/info/)
• Alternative installations (like custom PHP builds)
• System update daemons

Option 1: Reconcile Library Paths

$ sudo update-alternatives --config libcurl.so
$ sudo ldconfig -v | grep curl

Option 2: Force System to Use Package Version

$ sudo rm /usr/local/lib/libcurl.*
$ sudo apt-get install --reinstall libcurl3
$ sudo ldconfig

Option 3: Recompile with Version Info

If you need the custom version, rebuild with proper version tags:

$ ./configure --with-version-symbols
$ make clean
$ make
$ sudo make install

Add this to your /etc/ld.so.conf.d/custom.conf:

/usr/lib/x86_64-linux-gnu
/usr/local/lib

Then run:

$ sudo ldconfig

Verify the fix with:

$ ldd $(which curl) | grep curl
$ strings /usr/local/lib/libcurl.so.4 | grep CURL

The output should now show proper version information when present.

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When working with curl on Ubuntu 14.04 (Trusty), you might encounter this puzzling warning that appears in system logs and cron emails:

curl: /usr/local/lib/libcurl.so.4: no version information available (required by curl)

What makes this particularly strange is that the file keeps regenerating even after deletion, typically around 8:00 AM after daily cron jobs execute.

The root issue stems from having multiple curl installations conflicting with each other. Your system shows:

$ apt --installed list | grep 'curl'
curl/trusty-updates,trusty-security,now 7.35.0-1ubuntu2.5 amd64 [installed]
libcurl3/trusty-updates,trusty-security,now 7.35.0-1ubuntu2.5 amd64 [installed]

Meanwhile, there's a manually compiled version in /usr/local/lib:

libcurl.so.4 -> libcurl.so.4.3.0
libcurl.so.4.3.0

The symbolic link recreation suggests either:

• A cron job running ldconfig
• A package maintenance script
• Some application's post-install routine

Here are three approaches to permanently resolve this:

Option 1: Remove Compilation Artifacts

If you don't need the manually compiled version:

sudo rm /usr/local/lib/libcurl.*
sudo ldconfig

Option 2: Recompile with Version Information

If you need the local version, rebuild with proper versioning:

wget https://curl.haxx.se/download/curl-7.68.0.tar.gz
tar -xvzf curl-7.68.0.tar.gz
cd curl-7.68.0
./configure --prefix=/usr/local --with-ssl
make
sudo make install

Option 3: Redirect Library Path

Modify ldconfig to prioritize system libraries:

sudo echo "/usr/lib/x86_64-linux-gnu" > /etc/ld.so.conf.d/curl-x86_64.conf
sudo ldconfig

After implementing any solution, verify with:

ldd $(which curl) | grep curl
curl --version

The output should show the system libcurl and version information should appear properly.