On Alpha platform MAP_FIXED_NOREPLACE is defined as 0x200000, not as 0x100000 default provided by OpenJDK:

// Note that the value for MAP_FIXED_NOREPLACE differs between architectures, but all architectures
// supported by OpenJDK share the same flag value.
#define MAP_FIXED_NOREPLACE_value 0x100000

This causes the static assertion to fail during the compilation:

/<<PKGBUILDDIR>>/src/hotspot/os/linux/os_linux.cpp:2994:37: error: static assertion failed: MAP_FIXED_NOREPLACE == MAP_FIXED_NOREPLACE_value
 2994 | STATIC_ASSERT(MAP_FIXED_NOREPLACE == MAP_FIXED_NOREPLACE_value);
/<<PKGBUILDDIR>>/src/hotspot/share/utilities/debug.hpp:290:44: note: in definition of macro ‘STATIC_ASSERT’
  290 | #define STATIC_ASSERT(Cond) static_assert((Cond), #Cond)
      | ^~~~
/<<PKGBUILDDIR>>/src/hotspot/os/linux/os_linux.cpp:2994:37: note: the comparison reduces to ‘(2097152 == 1048576)’
 2994 | STATIC_ASSERT(MAP_FIXED_NOREPLACE == MAP_FIXED_NOREPLACE_value);
/<<PKGBUILDDIR>>/src/hotspot/share/utilities/debug.hpp:290:44: note: in definition of macro ‘STATIC_ASSERT’
  290 | #define STATIC_ASSERT(Cond) static_assert((Cond), #Cond)
  
See[1].

[1] https://buildd.debian.org/status/fetch.php?pkg=openjdk-24&arch=alpha&ver=24%7E22ea-1&stamp=1730843640&raw=0