Known Issues
Issue with GNU Linker
When running build.sh script with Free Pascal 3.0.4, you may encounter following warning:
/usr/bin/ld: warning: public/link.res contains output sections; did you forget -T?
This is known issue between Free Pascal and GNU Linker. See FAQ: link.res syntax error, or “did you forget -T?”
However, this warning is minor and can be ignored. It does not affect output executable.
To remedy, just upgrade Free Pascal and binutils.
Issue with development tools library search path
When running build.sh script, you may encounter following minor warning:
Warning: "crtbegin.o" not found, this will probably cause a linking failure
Warning: "crtend.o" not found, this will probably cause a linking failure
This is mostly because you install Free Pascal compiler before install development tools library.
First, you need to locate development tools library path on your computer. Run
# find / -name crtbegin.o
For example, in my Centos 7, command above will output (yours may be different)
/usr/lib/gcc/x86_64-redhat-linux/8/32/crtbegin.o
/usr/lib/gcc/x86_64-redhat-linux/8/crtbegin.o
Edit Free Pascal main configuration, /etc/fpc.cfg file and add following lines
#ifdef cpui386
-Fl/usr/lib/gcc/x86_64-redhat-linux/8/32
#endif
#ifdef cpux86_64
-Fl/usr/lib/gcc/x86_64-redhat-linux/8
#endif
Issue on FreeBSD
On FreeBSD 12, if you compile Free Pascal from source or tar file, you may get error when you try to run Fano web application executable.
$ ./bin/app.cgi
Segmentation fault (core dumped)
This is Free Pascal issue. Try to update to latest FreeBSD and install latest binutils
$ sudo pkg install binutils
and then rebuild the application, if the error does not go away, you may want to symlink ld to point to GNU linker /usr/bin/ld.bfd as a workaround.
If you can not find ld.bfd in /usr/bin, you may want to check other directories such as /usr/local/bin.
$ sudo ln -s -f /usr/bin/ld.bfd /usr/bin/ld
When linker ld is symlinked to LLVM linker /usr/bin/ld.lld (default), sometime, this cause segmentation fault when project is using cthreads unit.
However, latest binutils on newer FreeBSD releases no longer ships with ld.bfd.
Other workaround you may try is to install Free Pascal from FreeBSD package manager
$ sudo pkg install fpc
Issue with Free Pascal 3.2.0
When upgrading Free Pascal from 3.0.4 to 3.2.0, you may notice that Free Pascal 3.2.0 will generate several notes regarding inline methods it can not inline while in Free Pascal 3.0.4 there was no such notes generated.
When you compile examples program from Examples page with development build type, (i.e, you run build script with BUILD_TYPE=dev),
$ BUILD_TYPE=dev ./build.sh
You may find that compilation will stop with Free Pascal 3.2.0 compiler. This is because in development build, we use compiler options Sewn which will stop compilation when any error, warning or notes are generated.
#----------------------------------------------
# halt compiler after error, warning and notes
#----------------------------------------------
-Sewn
To remedy the situation, just edit build.dev.cfg file in example root directory and replace Sewn to Sew so that compilation will not stop on notes.
Missing Libmicrohttpd development package
If you create libmicrohttpd-based web application and get linking error
/usr/bin/ld : cannot find -lmicrohttpd
when running build.sh script.
You need to install libmicrohttpd development package. For Debian-based distribution,
$ sudo apt install libmicrohttpd-dev
For Fedora-based distribution,
$ sudo yum install libmicrohttpd-devel
For FreeBSD,
$ sudo pkg install libmicrohttpd
On FreeBSD 12, libmicrohttpd library is installed in /usr/local/lib which is not default directory where linker looks for library. If you get error
ld-elf.so.1: Shared object "libmicrohttpd.so.12" not found
when you run your application, make sure that /usr/local/lib is included in linker library directory, for example by setting LD_LIBRARY_PATH variable
$ export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib
$ sudo ldconfig
or you can use FreePascal -Fl command line parameter, for example -Fl/usr/local/lib, after that rebuild application.
Missing Libcurl development package
If you use curl-based http client and get linking error
/usr/bin/ld : cannot find -lcurl
when running build.sh script. You need to install libcurl development package. For Debian-based distribution,
$ sudo apt install libcurl4-gnutls-dev
Missing /etc/fpc.cfg
build.sh script that Fano CLI generates for each project, needs /etc/fpc.cfg. If you install Free Pascal to non default directory or using tool such as fpcupdeluxe, it may show error about missing /etc/fpc.cfg file or Fatal: Can't find unit system used by ... error. To remedy this situation, just create symbolic link in /etc directory to actual fpc.cfg file. For example,
$ sudo ln -s ~/fpcupdeluxe/fpc/bin/x86_64-linux/fpc.cfg /etc/fpc.cfg
or if you can not do that, you may want to use shell script provided by fpcupdeluxe when build.
$ FPC_BIN=~/fpcupdeluxe/fpc/bin/x86_64-linux/fpc.sh ./build.sh
Missing MySQL client library
If you encounter error Can't load default MySQL library ("libmysqlclient.so.20" or "libmysqlclient.so"). Check your installation, you need to install MySQL client development library. For example on Debian,
$ sudo apt install libmysqlclient-dev
Missing ODBC client library
If you use ODBC to connect to a database server and you encounter error
Can not load ODBC client. Is it installed? (libodbc.so)
Install unixodbc and unixodbc-dev
sudo apt install unixodbc unixodbc-dev
Memory leak due to database shutdown.
When Fano Framework web application is connected to a database server, and then database shuts down while application is still running. When application shuts down, it leaks memory. This issue is related to Free Pascal bug report 37993. Memory leak only happens when database shuts down and never restart. Memory leak does not happen when database server shuts down and then restarts or when database does not runs at all.
Indy memory leak issue.
When using Indy library, you need to be aware of Indy’s intentional memory leak issue. To avoid memory leak, you need to enable
conditional compilation define FREE_ON_FINAL in all IdCompilerDefines.inc inside Indy library, which is disabled by default.
From
{.$DEFINE FREE_ON_FINAL}
{$UNDEF FREE_ON_FINAL}
to
{$DEFINE FREE_ON_FINAL}
{.$UNDEF FREE_ON_FINAL}
Indy library also cause some warnings to be emitted during compilation. If your project is created using Fano CLI which by default use -Sew configuration for development type build (See build.dev.cfg) to stop compilation on error or warning.
This may cause compilation to stop, so if you use Indy, you may want to make it relax by using -Se configuration which stops only on error.
Fano web application with TFpHttpServer compiled with FPC 3.0.4 returns empty response.
Before version 1.14.1, Fano web application using TFpHttpServer and is compiled with FPC 3.0.4 will return empty response. This is bug and it is caused by different behavior of FileExists() between FPC 3.0.4 and FPC 3.2.0.
In FPC 3.0.4 or older, FileExists() in Linux/Unix returns true if input name is existing file or directory. In FPC 3.2.0, FileExists() in Linux/Unix returns false if input name is existing directory.