Merge #20527: build: Do not ignore Homebrew's SQLite on macOS

c932e0d doc: Update wallet database installation guide for macOS (Hennadii Stepanov)
ee7b84e build: Use Homebrew's sqlite package if it is available (Hennadii Stepanov)
c96d1f6 build, refactor: Check that Homebrew's qt5 package is actually installed (Hennadii Stepanov)

Pull request description:

  On master (7ae86b3) installed Homebrew `sqlite` package is ignored during build on macOS.

  This PR fixes this issue and update macOS build docs.

  Closes #20498.

ACKs for top commit:
  willcl-ark:
    > > That said, another tACK of [c932e0d](bitcoin/bitcoin@c932e0d)
  hebasto:
    > That said, another tACK of [c932e0d](bitcoin/bitcoin@c932e0d)
  laanwj:
    Code review ACK c932e0d
  jonasschnelli:
    code review re-ACK c932e0d

Tree-SHA512: 2563f25534d065556b17ee8c0fca957aea61b5ae288a2aa72743e77607843a45c39f209321e0f05b34283a74d2edcf961cf1dc54a35ed0cc21182304bb961505

Author: jonasschnelli

configure.ac

@@ -645,16 +645,19 @@ case $host in
          dnl It's safe to add these paths even if the functionality is disabled by
          dnl the user (--without-wallet or --without-gui for example).
 
-         qt5_prefix=$($BREW --prefix qt5 2>/dev/null)
-         if $BREW list --versions berkeley-db4 >/dev/null && test "x$BDB_CFLAGS" = "x" && test "x$BDB_LIBS" = "x" && test "$use_bdb" != "no"; then
+         if test "x$use_bdb" != xno && $BREW list --versions berkeley-db4 >/dev/null && test "x$BDB_CFLAGS" = "x" && test "x$BDB_LIBS" = "x"; then
            bdb_prefix=$($BREW --prefix berkeley-db4 2>/dev/null)
            dnl This must precede the call to BITCOIN_FIND_BDB48 below.
            BDB_CFLAGS="-I$bdb_prefix/include"
            BDB_LIBS="-L$bdb_prefix/lib -ldb_cxx-4.8"
          fi
-         if test x$qt5_prefix != x; then
-           PKG_CONFIG_PATH="$qt5_prefix/lib/pkgconfig:$PKG_CONFIG_PATH"
-           export PKG_CONFIG_PATH
+
+         if test "x$use_sqlite" != xno && $BREW list --versions sqlite3 >/dev/null; then
+           export PKG_CONFIG_PATH="$($BREW --prefix sqlite3 2>/dev/null)/lib/pkgconfig:$PKG_CONFIG_PATH"
+         fi
+
+         if $BREW list --versions qt5 >/dev/null; then
+           export PKG_CONFIG_PATH="$($BREW --prefix qt5 2>/dev/null)/lib/pkgconfig:$PKG_CONFIG_PATH"
          fi
        fi
      else

doc/build-osx.md

@@ -19,7 +19,7 @@ Then install [Homebrew](https://brew.sh).
 
 ## Dependencies
 ```shell
-brew install automake berkeley-db4 libtool boost miniupnpc pkg-config python qt libevent qrencode sqlite
+brew install automake libtool boost miniupnpc pkg-config python qt libevent qrencode
 ```
 
 If you run into issues, check [Homebrew's troubleshooting page](https://docs.brew.sh/Troubleshooting).
@@ -30,7 +30,22 @@ If you want to build the disk image with `make deploy` (.dmg / optional), you ne
 brew install librsvg
 ```
 
-## Berkeley DB
+The wallet support requires one or both of the dependencies ([*SQLite*](#sqlite) and [*Berkeley DB*](#berkeley-db)) in the sections below.
+To build Bitcoin Core without wallet, see [*Disable-wallet mode*](#disable-wallet-mode).
+
+#### SQLite
+
+Usually, macOS installation already has a suitable SQLite installation.
+Also, the Homebrew package could be installed:
+
+```shell
+brew install sqlite
+```
+
+In that case the Homebrew package will prevail.
+
+#### Berkeley DB
+
 It is recommended to use Berkeley DB 4.8. If you have to build it yourself,
 you can use [this](/contrib/install_db4.sh) script to install it
 like so:
@@ -41,7 +56,11 @@ like so:
 
 from the root of the repository.
 
-**Note**: You only need Berkeley DB if the wallet is enabled (see [*Disable-wallet mode*](/doc/build-osx.md#disable-wallet-mode)).
+Also, the Homebrew package could be installed:
+
+```shell
+brew install berkeley-db4
+```
 
 ## Build Bitcoin Core
 
@@ -72,14 +91,14 @@ from the root of the repository.
     make deploy
     ```
 
-## `disable-wallet` mode
+## Disable-wallet mode
 When the intention is to run only a P2P node without a wallet, Bitcoin Core may be
-compiled in `disable-wallet` mode with:
+compiled in disable-wallet mode with:
 ```shell
 ./configure --disable-wallet
 ```
 
-In this case there is no dependency on Berkeley DB 4.8 and SQLite.
+In this case there is no dependency on [*Berkeley DB*](#berkeley-db) and [*SQLite*](#sqlite).
 
 Mining is also possible in disable-wallet mode using the `getblocktemplate` RPC call.