python3: error on host python path too long

Error if shebang to host python interpreter would exceed 127 characters
(124 characters plus shebang and newline). This is used to alert user
when python-installer would fail to correctly set a Python program's
shebang line.

Closes: https://github.com/openwrt/packages/issues/28310
Signed-off-by: Daniel F. Dickinson <redacted>

diff --git a/lang/python/python3-package.mk b/lang/python/python3-package.mk
index 3300f1beabe39c2c5651b100896c7f8c4369e108..819b6bf64aa309b39a78bf64c430f0b29d760559 100644 (file)
--- a/lang/python/python3-package.mk
+++ b/lang/python/python3-package.mk
@@ -22,6 +22,23 @@ PYTHON3PATH:=$(PYTHON3_LIB_DIR):$(STAGING_DIR)/$(PYTHON3_PKG_DIR):$(PKG_INSTALL_
 
 -include $(PYTHON3_LIB_DIR)/openwrt/Makefile-vars
 
+# Error if shebang to host python interpreter would exceed 127 characters
+# (124 characters plus shebang and newline)
+# This is used to alert user when python-installer would fail to correctly
+# set a Python program's shebang line.
+# See https://github.com/openwrt/packages/issues/28310
+PYTHON3_PKG_HOST_BIN_MAX_PATH_LEN:=124
+
+define CheckHostPythonShebang
+       set -e; \
+       HOST_PYTHON3_BIN="$(HOST_PYTHON3_BIN)"; \
+       if \
+               [ $$$${#HOST_PYTHON3_BIN} -gt $(PYTHON3_PKG_HOST_BIN_MAX_PATH_LEN) ]; then \
+               echo >&2 "Path to host python too long; python program install would fail";\
+               exit 1; \
+       fi
+endef
+
 # These configure args are needed in detection of path to Python header files
 # using autotools.
 CONFIGURE_ARGS += \
@@ -264,6 +281,7 @@ define Py3Build/Compile/Default
 endef
 
 define Py3Build/Install/Default
+       $(call CheckHostPythonShebang)
        $(call Python3/Run, \
                $(PKG_BUILD_DIR), \
                -m installer \