diff --git a/desktop/posix.cpp b/desktop/posix.cpp
index 4ecf76c..c4a101f 100644
--- a/desktop/posix.cpp
+++ b/desktop/posix.cpp
@@ -419,6 +419,20 @@ long EsPOSIXSystemCall(long n, long a1, long a2, long a3, long a4, long a5, long
 			}
 		} break;
 
+		case SYS_faccessat: {
+			if (*(char *) a2 == '/') {
+				// We don't support file permissions yet, so just check the file exists.
+				int fd = EsPOSIXSystemCall(SYS_open, a2, O_PATH, 0, 0, 0, 0);
+				if (fd < 0) returnValue = fd;
+				else {
+					returnValue = 0;
+					EsPOSIXSystemCall(SYS_close, fd, 0, 0, 0, 0, 0);
+				}
+			} else {
+				EsPanic("Unsupported relative faccessat.\n");
+			}
+		} break;
+
 		case SYS_lstat:
 		case SYS_stat: {
 			int fd = EsPOSIXSystemCall(SYS_open, a1, O_PATH, 0, 0, 0, 0);
diff --git a/kernel/posix.cpp b/kernel/posix.cpp
index 989eb28..058507a 100644
--- a/kernel/posix.cpp
+++ b/kernel/posix.cpp
@@ -118,7 +118,7 @@ namespace POSIX {
 	}
 
 	intptr_t Write(POSIXFile *file, K_USER_BUFFER void *base, size_t length, bool baseMappedToFile) {
-		if (file->posixFlags & O_APPEND) {
+		if ((file->posixFlags & O_APPEND) && file->type == POSIX_FILE_NORMAL) {
 			// TODO Make this atomic.
 			file->offsetIntoFile = file->node->directoryEntry->totalSize;
 		}
@@ -241,7 +241,7 @@ namespace POSIX {
 				const char *devZero = "/dev/zero";
 				const char *devNull = "/dev/null";
 
-				// EsPrint("Open: %s, %x\n", pathLength, path, flags);
+				EsPrint("Open: %s, %x\n", pathLength, path, flags);
 
 				if ((EsCStringLength(devZero) == pathLength && 0 == EsMemoryCompare(path, devZero, pathLength))) {
 					file->type = POSIX_FILE_ZERO;
@@ -329,6 +329,14 @@ namespace POSIX {
 					handleTable->ModifyFlags(syscall.arguments[0], syscall.arguments[2]);
 				} else if (syscall.arguments[1] == F_GETFL) {
 					return file->posixFlags;
+				} else if (syscall.arguments[1] == F_SETFL) {
+					if (syscall.arguments[2] == O_APPEND) {
+						file->posixFlags |= O_APPEND;
+					} else if (syscall.arguments[2] == 0) {
+						file->posixFlags &= ~O_APPEND;
+					} else {
+						KernelPanic("POSIX::DoSyscall - Unimplemented F_SETFL %d.\n", syscall.arguments[2]);
+					}
 				} else if (syscall.arguments[1] == F_DUPFD) {
 					// Duplicate with FD_CLOEXEC clear.
 					OpenHandleToObject(file, KERNEL_OBJECT_POSIX_FD, 0);
diff --git a/util/build.c b/util/build.c
index 4b7c2a6..dd4e113 100644
--- a/util/build.c
+++ b/util/build.c
@@ -55,7 +55,6 @@ bool foundValidCrossCompiler;
 bool coloredOutput;
 bool encounteredErrors;
 bool interactiveMode;
-bool canBuildLuigi;
 volatile int emulatorTimeout;
 volatile bool emulatorDidTimeout;
 #ifdef __linux__
@@ -2030,9 +2029,6 @@ int main(int _argc, char **_argv) {
 	printf("Enter 'help' to get a list of commands.\n");
 	char *prev = NULL;
 
-	canBuildLuigi = !CallSystem("gcc -o bin/luigi.h.gch util/luigi.h -D UI_IMPLEMENTATION -D UI_LINUX 2> /dev/null");
-	unlink("bin/luigi.h.gch");
-
 	while (true) {
 		char *l = NULL;
 		size_t pos = 0;