Solves https://github.com/termux/termux-app/issues/608. @michalbednarski found the solution.
Not sure if this will have any other side effects.
TERMUX_PKG_HOMEPAGE=https://www.gnu.org/software/emacs/
TERMUX_PKG_DESCRIPTION="Extensible, customizable text editor-and more"
TERMUX_PKG_VERSION=25.3
TERMUX_PKG_HOMEPAGE=https://www.gnu.org/software/emacs/
TERMUX_PKG_DESCRIPTION="Extensible, customizable text editor-and more"
TERMUX_PKG_VERSION=25.3
TERMUX_PKG_SHA256=253ac5e7075e594549b83fd9ec116a9dc37294d415e2f21f8ee109829307c00b
TERMUX_PKG_SRCURL=https://mirrors.kernel.org/gnu/emacs/emacs-${TERMUX_PKG_VERSION}.tar.xz
TERMUX_PKG_DEPENDS="ncurses, gnutls, libxml2"
TERMUX_PKG_SHA256=253ac5e7075e594549b83fd9ec116a9dc37294d415e2f21f8ee109829307c00b
TERMUX_PKG_SRCURL=https://mirrors.kernel.org/gnu/emacs/emacs-${TERMUX_PKG_VERSION}.tar.xz
TERMUX_PKG_DEPENDS="ncurses, gnutls, libxml2"
TERMUX_PKG_EXTRA_CONFIGURE_ARGS+=" ac_cv_lib_elf_elf_begin=no"
# implemented using dup3(), which fails if oldfd == newfd
TERMUX_PKG_EXTRA_CONFIGURE_ARGS+=" gl_cv_func_dup2_works=no"
TERMUX_PKG_EXTRA_CONFIGURE_ARGS+=" ac_cv_lib_elf_elf_begin=no"
# implemented using dup3(), which fails if oldfd == newfd
TERMUX_PKG_EXTRA_CONFIGURE_ARGS+=" gl_cv_func_dup2_works=no"
+# disable setrlimit function to make termux-am work from within emacs
+TERMUX_PKG_EXTRA_CONFIGURE_ARGS+=" ac_cv_func_setrlimit=no"
TERMUX_PKG_HOSTBUILD=yes
TERMUX_PKG_KEEP_INFOPAGES=yes
TERMUX_PKG_HOSTBUILD=yes
TERMUX_PKG_KEEP_INFOPAGES=yes