[fpc-pascal] libc error on older Linux

[Tomas Hajny]

On 2026-06-03 12:10, Karoly Balogh via fpc-pascal wrote:
> Hi,
> 
> On Wed, 3 Jun 2026, Rainer Stratmann via fpc-pascal wrote:
> 
>> The freepascal program is compiled on Debian 13.
>> Lazarus: 4.0
>> Freepascal Version: I can not found.
>> 
>> Trying to run the program on Debian 11 shows the error
>> 
>> [prgname]: /lib/x86_64-linux-gnu/libc.so.6: version 'GLIBC_2.34' not 
>> found
>> (required by [prgname])
>> 
>> ? ? ?
> 
> This isn't a Free Pascal issue, this is a "welcome to Linux" issue.
> 
> Your code, or code that gets included in your software either by 
> Lazarus
> or Free Pascal as part of their respective libraries, uses 
> functionality
> that are only available in glibc 2.34 or newer. It won't work on Debian
> 11, that shipped with glibc 2.31.
> 
> Without knowing more about what your project tries to do, it's not 
> really
> possible to tell, if there are any easy solutions to get around this,
> apart from upgrading the target system...

...or compiling on the lowest version you intend to support, or creating 
programs not using libc (which is possible with FPC even when targetting 
Linux, but with limitations which make this theoretical option 
impossible for Lazarus applications).

Tomas