building perl fails to create the Makefile

...
cflags.SH: cc       = gcc                                                                                                                          
cflags.SH: ccflags  = -march=x86-64 -mtune=generic -O2 -pipe -fwrapv -fno-strict-aliasing -fstack-protector-strong -march=x86-64 -mtune=generic -O2
 -pipe -fwrapv                                                                                                                                     
cflags.SH: stdflags =                                                                                                                              
cflags.SH: optimize = -march=x86-64 -mtune=generic -O2 -pipe                                                                                       
cflags.SH: warn     =  -Wall -Werror=declaration-after-statement -Wextra -Wc++-compat -Wwrite-strings                                              
Extracting cflags (with variable substitutions)                                                                                                    
Extracting config.h (with variable substitutions)                                                                                                  
Extracting makedepend (with variable substitutions)                                                                                                
Extracting Makefile (with variable substitutions)                                                                                                  
./op.c: line 3: amigaos4: command not found                                                                                                        
./op.c: line 4: syntax error near unexpected token `('                                                                                             
./op.c: line 4: ` *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,'                                                  
./perl.c: line 3: amigaos4: command not found                                                                                                      
./perl.c: line 4: syntax error near unexpected token `('                                                                                           
./perl.c: line 4: ` *    Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001'                                                       
Extracting myconfig (with variable substitutions)                                                                                                  
Extracting pod/Makefile (with variable substitutions)                                                                                              
Extracting Policy.sh (with variable substitutions)                                                                                                 
Extracting runtests (with variable substitutions)                                                                                                  
Configure done.                                                                                                                                    
                                                                                                                                                   
If you compile perl5 on a different machine or from a different object                                                                             
directory, copy the Policy.sh file from this object directory to the                                                                               
new one before you run Configure -- this will help you with most of                                                                                
the policy defaults.                                                                                                                               
                                                                                                                                                   
make: *** No targets specified and no makefile found.  Stop.                                                                                       
==> ERROR: A failure occurred in build().                                                                                                          
    Aborting...                                                                                                                                    
                                                                                                                                                   ```

Reproduce the failure from the package build and inspect the Configure output around extraction of op.c, perl.c, and Makefile. Check why the generated source files are being interpreted as shell input; done means Configure creates a usable Makefile and make proceeds without the reported errors.